How do I write a VB macro or procedure that will get the contents of cell E37
from workbook named E40 if E37 is not blank?

This is the formula that I have in the target cell:
=IF('C:\Documents and Settings\[E40.xls]E40'!$E$370,+'C:\Documents and
Settings\[E40.xls]E40'!$E$37,0)

That formula works, but I think I need a case select type of code to move
onto cell $E$38, if cell E37 is blank, then to
$E$39 if E38 is blank. If E39 is not blank, then plus that cell in the
target cell.

Sound complicated? It is -- I can't seem to understand how to make this
happen. Can someone help me?