I'm really hoping someone might be able to point me in the right direction
with this one because I'm pretty sure that Excel can do this, but just can't
remember how.

I would like to design a form in Excel that will be initiated by various
employees. However, they will only complete one part of the form. The
Accounts Payable department will then complete the rest of the form to prove
that they've acted on it. I would like the contents of every form to be
updated into a master spreadsheet for tracking purposes at two intervals -
when the initial employee fills the top portion, and then again when it is
completed by the accounts payable department.

I forsee designing a template that comes up when users click "File, New".
When the file is saved, the master spreadsheet will be updated with whatever
data they've entered. Then when the next person saves, the master
spreadsheet will update with the additional information. It would also be
useful if the master could track which user filled out which fields.

Any help would be greatly appreciated. Thanks so much!!