Xls formula to static value

Hello.

I'm working on one report which can be downloaded via web app as pdf or xls file.

I'm using in this report xls formula to count sth. Ofcourse when it's exported to pdf file there is no possibility that pdf will count itselfs this value from xls formula.

So, there is my question, is there any way to automaticly convert formula into counted static value when report is exported to pdf?

Or maybe creating 2 fields, one with formula and second with already counted value, where one field or another is hidden depends on what kind of export did we choose?