For my cypher program, QFIBCODE, I need something that can take letters and turn them into numbers (and back again) for the user, so they don't have to remember that A=1, B=2, etc. for themselves, the calculator does the translating for them.

Ya, that seems like a pretty easy task actually. To go from letter to number you something like Graphmastur said:

{4,4→dim([A] \\Using your matrix idea as a basis. I don't know how you have things set up though.
1→B
1→C
For(A,1,length("ABCDFGHIJKLMNOPQ
inString("ABCDEFGHIJKLMNOPQRSTUVWXYZ",sub(Str1,A,1→[A](B,C
B+1-4(B=4→B
C+(B=1→C
End
And to go from number to letter:

"_ \\The underscore symbolizes a space.
For(A,1,4
For(B,1,4
Ans+sub("ABCDEFGHIJKLMNOPQRSTUVWXYZ",[A](A,B),1
End
End
sub(Ans,2,length(Ans)-1→Str1
Those both should work, but I just made them on the spot and didn't test them. You might have to flip some things around but the principle remains the same.

Haven't had a chance to test it yet.