How to update a column in a K2 Task

I'd like to update a SharePoint column in the task itself generated by K2 before the user actions it. In this case it would simply update a text column with the ID from the list item which the approval task is related to. Can I do this during the time of the task creation in the Integration Client, or can I do this in a List Item? If in a List item how do I find the ID of the task just generated?