Hi,
Installing K2 for SharePoint is the easiest solution to accomplish this.
If for some reason you cannot install K2 for SharePoint, then the only other option I can think of is to create your own custom service broker to achieve this.
SharePoint should have exposed some list functions via a web service (<sharepoint url>/_vti_bin/Lists.asmx?wsdl), so you can use that to create your own service broker to interact with SharePoint Lists.
References:
PS: You may be wondering why not use Endpoint Web Service or EndPoint WCF to register the Lists.asmx.wsdl, and create SmartObjects that will use this web service. While you can certainly create Web Service or WCF service instance to use SharePoint List web service, you will encounter trouble when trying to execute the SmartObjects. I have been playing with this for a while, and I cannot find the correct input format to add new list items to my list. Maybe someone here have better luck on getting this to work.
Thanks for the reply Nerd....Reason for not installing K2 for Sharepoint is we have only 1 Sharepoint environment whereas we have more than 1 k2 environment. So could you please give an idea how to configure to allow multiple K2 Servers to use the same SharePoint online?