in reply to Parsing CCL (Common Command Language) commands
Since you didn't specify a particular database, I assume you're free to choose. In that case I would suggest MySQL, since it has this nice RegExp feature, where you can query according to some (simplified) regular expression.
This would allow you to convert your parse tree into a valid (MySQL) regexp. Simply select everything which looks like your regexp and your finished.
Hope it helps (a bit),
"A chicken is an egg's way of producing more eggs."