Hi ,
I am sorry but I cannot think of any possibility other than a VBA procedure , to make your of changing all the CF formulae easier.
However , as I understand it , both the cell formulae and the CF formulae need to be changed ; since the CF formulae will be based on the cell values , if the incorporation of the IFERROR functions in the formulae return 0 , then the CF formulae may not need to be changed. Have you tried changing one cell formula and seeing this ?
Narayan