You don't need "extensive experience with parsers" to do what the OP is describing. Lex and yacc (and their moral equivalents in other languages) were written

You don't need "extensive experience with parsers" to do what the OP is describing. Lex and yacc (and their moral equivalents in other languages) were written precisely so that a programmer of ordinary skill could write a parser and feel reasonably confident that it would behave properly. I've done this kind of thing more than once, even back when I was fairly junior as a programmer.