Data validation in if statement

Hi...

I am trying to put value from data validation into if statement
e.g. if the data validation is "Jan", then formula like: =IF(Jan!11="","",Jan!F11), if i the data validation is "Feb" then the formula become like: =IF(Feb!F11="","",Feb!F11)
so I can run it like a normal IF statement, is there a way?

Thanks for your time...