I am sending a link for a survey (webform 3.x) to users. Based on a variety of information, they receive a link in the format http://www.domain.com/group/userid. I'm able to retrieve the /group easily and process this into a hidden field on my webform. However, the page "/group/userid" does not exist. I need to find a way to rewrite the URL to go to /group?i=userid. I'm currently using clean URLs, but am open to changing. When I attempted the rewrite via htaccess, I lost the theme of my site (likely a path issue).
Is there a module for this sort of thing? Any suggestions?