spreadsheet?
The user wanted to convert the diagram to an an Excel
spreadsheet.
That doesn't help much.
Is this user aware that Excel is a spreadsheet program while Visio is (with some
imprecision) a drawing program? Generally, these are not interoperable sorts of
applications. At the very least, the user needs to give some sort of idea how
they imagine the Visio diagram would function in Excel.
If simply as an embedded image, then copying the image in Visio and pasting as a
picture into an Excel worksheet should work.
On the other hand, if the user wants an Excel spreadsheet to appear like the
Visio diagram, then they're out of luck. Not possible. They'd have to construct
the look-alike spreadsheet manually.
Otherwise, you need to pass along more details from your user.