I am trying to make a find and replace that will find ABS which is any time ABS() is used and replace it with a relative formula ...
I tried using the find and replace to replace all...which works but not in tandem with R1C1 style formulas. 

Sub FReplace()
    Cells.Replace What:="*ABS*", Replacement:= _
        "=IFERROR(IF(AND(RC[-6]=0,RC[-5]<>0),1,ABS(RC[-5]/RC[-6])),0)", LookAt:=xlPart, SearchOrder _
        :=xlByRows, MatchCase:=False, SearchFormat:=False, ReplaceFormat:=False
End Sub
So my next thought was a loop... as making it the found cell active first and doing a replace or entering the formula will work and have it go until it is past the last row count...
Could not get a loop to work but here is a code that works, and replaces the next cell in order in which they appear but requires hitting play over and over... I have thousands in various columns to replace... 

Sub FReplaceActive()
    Cells.Find(What:="*ABS*", After:=ActiveCell, LookIn:=xlFormulas, LookAt _
        :=xlPart, SearchOrder:=xlByRows, SearchDirection:=xlNext, MatchCase:= _
        False, SearchFormat:=False).Activate
    ActiveCell.FormulaR1C1 = _
        "=IFERROR(IF(AND(RC[-6]=0,RC[-5]<>0),1,ABS(RC[-5]/RC[-6])),0)"
End Sub

Fingers are crossed -

Cheers