You need the cursor to move down a cell each time - the extra line below
should do it:

Row = 1
With Sheets("Data")
Range("K2").Select
Do While .Range("D" & Row) < ""
ActiveCell.FormulaR1C1 = "=RC[-3]-RC[-5]"
activecell.offset(1,0).select
selection.NumberFormat = "dd h:mm:ss"
Row = Row + 1
Loop
End With

"Don Doan" wrote:

Hi,
I'm a beginner VB and I'm trying to modify this code so that it would
subtract column H against column F and put the resutl in column K...it should
do that until there is a blank space in column D. I can't seemed to get it
working...it only does H2-F2 and not for all the rows...any idea??

Row = 1
With Sheets("Data")
Range("K2").Select
Do While .Range("D" & Row) < ""
ActiveCell.FormulaR1C1 = "=RC[-3]-RC[-5]"
selection.NumberFormat = "dd h:mm:ss"
Row = Row + 1
Loop
End With