Online or offline Regex translator

Hi,

I use Expresso from ultrapico to try and understand how to phrase my Regex expressions for use into Trados.

Expresso provides a library of expressions that I use as a basis to create my own expressions but it is a trial and error process and - often - does not work because I might have to use two expressions from the library to create my own, and the combinaison simply ... does not work.

Is there an easier way?

Is there a piece of software that "translates" a full expression (35.6%) into a Regex pattern (\d{1,3})(%)?