<snip>
>the range property does not take numeric refrences like .range(999,2:999,60) it needs an alpha "A900:AH900" to do a copy, so I copy the first cell with the formula and then pase n times to the right the formla and it works.
<snip>

I don't know if it helps but it's easy to convert column number into column reference.

nCol = 222

* using Excel
cColRef = oWorkSeet.Cells(1,nCol).Address(.T.,.F.,1)
cColLetter = LEFT(cColRef, AT("$", cColRef)-1)

* VFP code only
cColLetter = IIF(nCol>26, CHR(Int((nCol - 1) / 26) + 64), "") + ;
              CHR(((nCol - 1) % 26) + 65)