Maybe I'm misunderstanding what you meant, but I don't think you can do this in the general case (since parser combinators can describe languages that are more complicated than/not describable within regular languages).
https://github.com/dfhoughton/pidgin
As it says there, you can only build non-recursive grammars this way.
And the reason I wrote that crate:
https://github.com/dfhoughton/two-timer
And the reason I wrote that crate:
https://github.com/dfhoughton/jobrog
And having written these crates, I went back to writing Ruby for my day job. I am not a very experienced rustacean, and what skill I developed writing these things has faded, but I use the last one daily, so the regex-based parser is still working pretty well.
* It's a "parser combinator library" inasmuch as it allows you to write reusable parsing rules that can be components of other rules.
Alternatively one can build a parser combinator library that compiles to a large Regex. That Regex would return a big Matcher, so a convenience wrapper for that would need to be made usable by a wrapper created from the same parser combinator.