Use the UsedRange of one sheet as the limit of a for each loop on another ?

Excel 2000 VBA.

How could I modify something like

For Each MyCell In MySheet.UsedRange
    -stuff
Next

So that during the loop MyCell points to a cell in a sheet other than
MySheet but in the same row, col position on the other sheet.  I want to
set-up a grid of formla on a new sheet (my code to do this is where -stuff
is).  Each cell of my grid will reference it's counterpart in MySheet, but I
will not know how much data MySheet will have on t until it is used at run
time.