Sorry to drag up this topic, but I am trying to acheive the exact same thing.

I do not need subdomains or mydomain.com/username

I simply need

/index.php?option=com_comprofiler&task=userProfile&user={USERNAME}

I have searched this forum until I am blue in the face. I have found lots about this style: mydomain.com/username

but cannot find the instructions on which files to edit to get this:

/index.php?option=com_comprofiler&task=userProfile&user={USERNAME}

Seeing as the people in this thread managed to do it, I was wondering if someone can point me in the correct direction?

Thanks.