i managed to get this macro working on a small database (6 by 10 instead of 3000 by 70), but it breaks down on a large scale file. "Method RANGE of object _GLOBAL failed".
I looked at the next post - about similar type of error reported, but i have no clue what i can qualify in the statement...

Cells(l, k).Formula = _
Application.Index(Workbooks(FileNameOnly(FMCFilena meOldRel)).Worksheets("DATABASE").Range("i2:bq2972 "), _
Application.Match(Cells(l, 9).Value, Range("aletters"), False), _
Application.Match(Cells(1, k).Value, Range("bletters"), False)).Formula

I am as confused as a baby in a topless bar