After 51 posts, I don't figure you're a trial user anymore?!? Welcome aboard.
In scripting, the GoToLayout step has an option for "by calculation".
The calculation can be If (Firm Data::Style = 10; "Firm Profile - B" ; "Firm Profile - A" )
Assuming you are on FMP10, you could run the script on record load (I'm not on 10 so I don't know the exact setting names for this)
Is this what you're after?
This is perfect, thank you! And no, I am no longer a trial user, but I've still got a LOT to learn...