Thought this might be of interest; below shows how the examples provided would look in Rebol:

    digits: digit: charset "0123456789"

    rule: [
        thru "$"
        some digits
        "."
        digit
        digit
    ]

    parse "$10.00" rule    ;; true


    pattern: [
        some "p"
        2 "q" any "q"
    ]

    new-rule: [
        2 pattern
    ]

    parse "pqqpqq" new-rule    ;; true

Rebol doesn't have regular expressions instead it comes with a parse dialect which is a TDPL - http://en.wikipedia.org/wiki/Top-down_parsing_language

Some parse refs: http://en.wikibooks.org/wiki/REBOL_Programming/Language_Feat... | http://www.rebol.net/wiki/Parse_Project | http://www.rebol.com/r3/docs/concepts/parsing-summary.html