Dim rngDataRange As Range

ActiveSheet.UsedRange.Select
Selection.Offset(0, 19).Select
Set rngDataRange = Selection

Range("T1").Select
Cells(1, 20).Copy
rngDataRange.Offset(0, 0).Resize(1, 1).Select
ActiveSheet.Paste
rngDataRange.Offset(0, 0).Select
Selection.FillDown

This is a portion of a macro I'm working on. The intent is to dump a
formula in cell T1, and use a fill down. Although this fill down
incorporates column T and 18 additional columns. What needs to be modified
to just have Column T fill down.