pass control to user while running macro

I need to pass control from a running macro to the user allowing them to edit values in a worksheet and them pass control back to the macro to continue processing.

Specifically the macro reads content from an external file (Bill of Material) , places select part numbers and quantities into a worksheet that requires the user to correct the quantity associated with those parts. When done reviewing/changing the data I want the macro to continue to run and finish performing subsequent work.

What I do not know how to do is pass control back to the user to allow him/her to edit the worksheet and then signal the macro that the work is done.

I would prefer not to go the route of a user form as it limits the user (to use scroll bars etc..).

How can you get the code to pause while waiting for input from the user?