I tried duplicating what you’re doing, but I was having issues setting up the Context Menu to launch Time and Expense Entry. Something with my test environment is wonky. The Context Menu Maintenance would keep showing entries I’ve deleted. 
I’ve done similar things with other forms. The key is customizing both forms so you can send a parameter from one form to the other and in the time entry automate the same events in the event tracking. I can prob help you and try a few things on a session (I don’t have access to an epicor environment right now). Good luck