Alright, so I found my basic answer from these posts, 2-3 years ago.
Steam has updated its website since then, so I've messed around with it and attempted to make it work.. this is currently what I have, and what I'm getting.
=REGEXEXTRACT(REGEXEXTRACT(CONCATENATE(IMPORTXML("https://steamcommunity.com/profiles/76561198103825553/games/", "//script")),"\(([Garry's Mod]+)\)"),"[0-9]+")&" hrs last two weeks"
Error Function REGEXEXTRACT parameter 2 value "[0-9]+" does not match text of Function REGEXEXTRACT parameter 1 value "o".