Well, no. I can't. I've never done such a thing. I understand that writing a compiler is a common assignment for a Computer Science course, so there ought to be a lot of information on the subject. I recently came across a question over at Stack Overflow regarding a book called "Let's Build a Compiler" by Jack Crenshaw, which is apparently considered a good place to start. A search engine should find it.
I understand that, these days, we don't even write our own "lexer" and "parser", but use tools like "flex" and "yacc" and "antlr" and "bison" to generate C code to write these parts of a compiler. A program to write a program to write a program. It's a million miles from the kind of programming that interests me. "Recursive descent" sounds to me like something you'd wish on your worst enemy, not something I'd want to do!
Using Nasm would probably be a bad idea, since it would lock you into x86. If you should decide to use Nasm, I'll be glad to help you with details, if I can.
Best,
Frank