It would be great if you can add a function "eval". This would be similar to R or access where you would pass a string to the eval function and it would then evaluate the string. My made up use case would be something like this: I have 1 Million rows of data with 20 fields. The first 10 are value1, value2...value10, and the second 10 are value1_right, value2_right....value10_right. I would like to replace valuex with valuex_right if valuex is null. With a multifield formula tool selected I could write something like this with value1-10 selected: eval("IIF(ISnull([_CurrentField_]),["+[_CurrentFieldName_]+"_right],[_CurrentField_])"). Thanks!