That problem is way to vaguely defined. I could come up with a dozen regexes that extract '00.01.00' from the above string, but each of them might fail with any other string.

You use regexes to extract patterns. But you cannot define a pattern by giving just one example, especially not if you say The version number isn't always the same!. There are thousands of ways to describe version numbers.

Unless you tell us what kind of pattern the version numbers have (or by which pattern the version numbers can be found in the strings), there's no guarantee what any of the doubtless many guesses presented in this thread will actually work on your production data.

You might get lucky, and you pick a regex that will work. But how will you know?

Abigail