I have zero PowerShell knowledge, but from what you describe you probably
want to use the named capture groups feature (?<NAME>...) (the original regex you
posted didn't contain any...).
This is still a
capture group just like a regular parenthesized grouping, but its name is
NAME.
I'd recommend you to look at some examples and while you're at it, you should also read part 1 of that wonderful
tutorial to understand how to access the various bits of information from a
successful match!
It's all there!