Yes, I understand. It used to be (perhaps it still is) fltplan.com would build a profile for you if the aircraft wasn't in their data base so long as requester furnished the data from the POH. I am assuming the OP has access to the POH.
Good for you! You'll have a lot of fun. Fltplan.com will build the aircraft profile for you if you e-mail them the relevant pages from the POH. At least they used to. You might want to check it out.
Calm down. High Flying A380 said in his post "I've always been told that ATC can't even see filed alternates." ATC can see filed alternates if the alternate is in the Remarks block. That's all.
I've been told the same thing; ATC doesn't see the filed alternates. What I include in the Remarks section is "WX ALT APT - KXYZ." This they do see, or so I've been told.
It has been awhile since I've flown a Proline 21 aircraft but I don't think reversing a stored flight plan was possible. Personally, I've never needed that function.