Nope, sorry. Files from professional software can not be converted to TurboTax files.
You will need to either start everything from scratch, or find another source to use ProSystem fx.
As a side note, if you use TurboTax, you may find using the "Forms Mode" of the CD/downloaded version may be easier to use than using the Step-by-Step mode (the online versions only have Step-by-Step mode).