Reset Dependent Data Validation selections without macros?

Actually, I think I acted a little too soon. I thought I had a solution where I could simply use this formula in the list definition for B2: "=IF(A2="","", Indirect(A2))", but it didn't work.

I fear Macros are required; I just need a way to retain them when I split the workbook. See this thread.

If anyone knows a way to reset these values without a macro, please chime in. If it isn't possible without VBA, then I still need a solution to the question in the thread linked above.