I have inhertied a sequential sharepoint workflow which deals with multiple tasks for different people; multi step approval based on certain condition..For each approval new task is created and monitored...For some reason; we have decided to use single task for the whole workflow and the single task will get assigned to required person at different stages...this will help us reduce the cluter in the task list

For refactoring it; I am trying to create "CreateOrUpdateTaskAndWaitForCompletition" activity...so that I can use this component multiple times as per given workflow. Create/Wait branch of my activity works fine; as I have the correlation token within the activity. But when I try two instances of this activity; task is created in first activity and it needs to be updated in second instance where I dont have the correlation token. In the second instance; (Update/Wait branch) I have tried updating the task through code activity but its not working and I am getting "This task is currently locked by a running workflow and cannot be edited" exception!

Can I use UpdateTask activity without correlation token? Can I programmatically update the workflow task? Can I programmatically unlock the workflow task?