Hello. I get the message "Reference is not Valid" when the following piece
of code executes from my program; k is an integer, focallength is a double,
and sheetname is a string:

sheetname = "r32-" & k + 1 & "-" & FocalLength

Dim infourierrng As Range
Dim outfourierrng As Range

Set infourierrng = Worksheets(sheetname).Range("J15:J1038")
Set outfourierrng = Worksheets(sheetname).Range("L15:L1038")

Application.Run "ATPVBAEN.XLA!Fourier", infourierrng, outfourierrng, False,
False

This message appears in a messagebox; if I click OK, everything proceeds
fine, and the fourier transform works, so it isn't really much of a problem,
except I don't want this message to appear anytime anyone runs this macro.
Any help would be greatly appreciated.