Im guessing this was supposed to be in a thread or something, but I'll make a couple of picky points cos its a slow.
Lex is a lexer (or rather, Lex makes a lexer), not a parser. The equivalent parser would be Yacc, I think. I don't know what you mean by saying it should be automated, it sort of is. And I believe Lex/Yacc generated code should run fine on the Gp32.