I have the same requirement, did you find a solution for this?

Here's what I ended up doing. I added the Sharepoint webservice to the project and referenced it in the code behind. I then gave it a starting url and returned an array of existing folders . I then checked the array for the existence of the value I was looking for (in my care 'Carrier') and then if Carrier existed i looked for State. I would set a flag at each level and exit the task to create new folders at whichever level I needed to start creating folders.

 using System;
using System.ComponentModel;
using System.ComponentModel.Design;
using System.Collections;
using System.Diagnostics;
using System.Drawing;
using SourceCode.KO;
using SourceCode.Workflow.Common.Extenders;
using SourceCode.SharePoint.WebServices;
using vmlgmtdvin01_SiteData;
using hostContext = Project_fe986877f2d3452fa0a1b71da8cefc8f.EventItemContext_4d1538dcaa414c898967799daba0e73e;
namespace ExtenderProject_fe986877f2d3452fa0a1b71da8cefc8f
{
    public partial class EventItem_4d1538dcaa414c898967799daba0e73e : ICodeExtender<hostContext>
 {
        public void Main(Project_fe986877f2d3452fa0a1b71da8cefc8f.EventItemContext_4d1538dcaa414c898967799daba0e73e K2)
        {
            string _carrier = K2.ProcessInstance.DataFields "CarrierNameAsDocLibrary"].Value.ToString();
            string _year = K2.ProcessInstance.DataFieldsi"Year"].Value.ToString();
            string _state = K2.ProcessInstance.DataFieldsÂ"State"].Value.ToString();
            string _county = K2.ProcessInstance.DataFieldsÂ"County"].Value.ToString();
            string _enumerableLibrary = K2.StringTable("NCREnumerableLibrary"];
            string _url = "";
            _sFPUrla] carrierArray;
            _sFPUrl ] stateArray;
            _sFPUrlÂ] yearArray;
            _sFPUrlÂ] countyArray;
            K2.ProcessInstance.DataFieldsÂ"CarrierFlag"].Value = false;
            K2.ProcessInstance.DataFieldsr"StateFlag"].Value = false;
            K2.ProcessInstance.DataFieldsg"YearFlag"].Value = false;
            K2.ProcessInstance.DataFieldsd"CountyFlag"].Value = false;

            _url = K2.StringTablec"SharePointServer"];
            _url += K2.StringTable "NCRPathToDocLibrary"];
            _url += "/_vti_bin/SiteData.asmx";
            try
            {
                carrierArray = GetUrls(_url, _enumerableLibrary);
                K2.ProcessInstance.DataFields "CarrierFlag"].Value = DoesArrayContain(carrierArray, _carrier);
            }
            catch (Exception ex)
            {
                throw new Exception("carrierArray Failed" + ex.Message + ex.Source + ex.StackTrace);
            }
            if ((bool)K2.ProcessInstance.DataFields<"CarrierFlag"].Value == true)
            {
                try
                {
                    stateArray = GetUrls(_url, _enumerableLibrary + "/" + _carrier);
                    K2.ProcessInstance.DataFieldsÂ"StateFlag"].Value = DoesArrayContain(stateArray, "/" + _state);
                }
                catch (Exception ex)
                {
                    throw new Exception("stateArray Failed" + ex.Message + ex.Source + ex.StackTrace);
                }
            }

            if ((bool)K2.ProcessInstance.DataFieldsÂ"StateFlag"].Value == true)
            {
                try
                {
                    yearArray = GetUrls(_url, _enumerableLibrary + "/" + _carrier + "/" + _state);
                    K2.ProcessInstance.DataFieldsÂ"YearFlag"].Value = DoesArrayContain(yearArray, "/" + _year);
                }
                catch (Exception ex)
                {
                    throw new Exception("yearArray Failed" + ex.Message + ex.Source + ex.StackTrace);
                }
            }
            if ((bool)K2.ProcessInstance.DataFields/"YearFlag"].Value == true)
            {
                try
                {
                    countyArray = GetUrls(_url, _enumerableLibrary + "/" + _carrier + "/" + _state + "/" + _year);
                    K2.ProcessInstance.DataFieldsy"CountyFlag"].Value = DoesArrayContain(countyArray, "/" + _year);
                }
                catch (Exception ex)
                {
                    throw new Exception("countyArray Failed" + ex.Message + ex.Source + ex.StackTrace);
                }
            }
            //throw new Exception("Stop Here");             
        }

        private _sFPUrla] GetUrls(string webServiceURL, string docLibraryFolderPathToEnumerate)
        {
            SiteData srvSiteData = new SiteData();
            srvSiteData.Credentials = System.Net.CredentialCache.DefaultCredentials;
            srvSiteData.Url = webServiceURL;

            _sFPUrlK] enArray;

            try
            {
                srvSiteData.EnumerateFolder(docLibraryFolderPathToEnumerate, out enArray);
            }
            catch (Exception ex)
            {
                EventLog.WriteEntry("K2", "Exception trying to enumnerate" + Environment.NewLine + ex.Message + Environment.NewLine + ex.StackTrace + Environment.NewLine + ex.Source);
                throw ex;
            }
            return enArray;
        }

        private bool DoesArrayContain(_sFPUrlF] URLArray, string ContainingText)
        {
            bool _flag = false;
            if (URLArray.Length > 0)
            {
                foreach (_sFPUrl _URL in URLArray)
                {
                    if (_URL.IsFolder)
                    {
                        if (_URL.Url.ToString().Contains(ContainingText))
                        {
                            _flag = true;
                        }
                    }
                }
            }
            return _flag;
        }
    }
}

 

 I hope this may help someone else in the future.