Please help me convert this nginx rewrite into Litespeed rewrite

I have the following nginx rewrite rule that works great, but for the life of me, I cannot figure out the right way to add it to Litespeed:

~^/index\.php\?(?<suffix>(forums|threads|members|resources|posts|help|tags|attachments).*)$ /forums/$suffix;
Here is what I added to Litespeed, but it's not hitting this rule, so my regex must be incorrect.
RewriteRule ^/index\.php\?((forums|threads|members|resources|posts|help|tags|attachments).*)$$1 [L,R=301]
Basically, this looks for URLs like and sends it to

I need it to only apply to these set suffixes though, because we have different software at the root now that also uses this /index.php?path format, which I need to keep working obviously.

Any help would be appreciated. I'm a long-time nginx user, and my Apache style rewrite skills are lacking.