I had a client scenario, where I needed to grab a 6-digit number from an incoming email subject. It wont always be in the same place, and also possibly not be the only digits. So I couldnt use trim, length or other that I could think off.

Unfortunately, or luckily, depending on how you look at it, my dear friend Cat Schneider introduced me to regex

Thankfully someone within my company helped me guide a regex expression I could use, but I do want to share this awesome resource:

Regex 101, an amazing site with explanations as well

However, I found out regex doesnt work in Power Automate Cloud. (It does work in RPA desktop flows)

This one took me a while, but I ended up finding this blog post: Regular Expression Support in Power Automate, via Custom Code Connector

Full credits to them, I used their swagger, and created a custom connector with it.

Then I added the step in my cloud flow, added in my regex, and I could do regex filtering on my subject!

I hope this helps, merely sharing for exposure, full credit to Steelcutbytes for this one!