Assign Task within Workflow - Updated

I am attempting to grab the user that completed a specific task and assign them subsequent tasks within the Workflow. I have the user that completed the specific task using:

Audit_User = (wt.org.WTUser)wt.session.SessionMgr.getPrincipal();

However, I am not exactly sure how to use this to assign the next task to this variable. Any help would be greatly appreciated.

Update: I got this to work by changing how the attribute got created for the subsequent task. I unselected the "Copy Into" selection on the task where the variable was to be used.