Auto numbering upon completion

I have an excel form that is set up to automatically route from one user to another for approval. Once it hits the last step, I need it to assign a number that sequences after each one comes through. Has anyone out there written any code to do such a thing?

Example: CEO (8th and final in line of the routing) approves capital requisition, pushes the button to send notice to everyone, SOMEHOW the number 010 is assigned to this requisition and is indicated on the email notice. The NEXT requisition he receives and approves will be 011, and so on.

I need this before Monday next week or :eek2:

They are all on a sheet yeah? So have a cell that uses the max function to get the last/highest number assigned. When CEO presses the approve button, it checks that number, adds one and saves it to the cell. Refresh the worksheet if required and the max number should increase.

The form is a template that saves itself as a new name each time the initiator sends it out. If I have the code access a seperate worksheet that had the Max Function in it would it update based on the number of times it was accessed?