1. I added CODE tags to your macro -- you can use the [#] incon next time to add them

2. No need to .Select or .Scroll - you can work directly on objects

3. This part 'looks wrong'

Formula1:="='Look up Tables'!Zi"

If I always = 20 then try

Formula1:="='Look up Tables'!Z20"


If not, then try

Formula1:="='Look up Tables'!Z" & i


Otherwise attach a workbook with the WHOLE macro and details