I have a client that wants to use EE to serve different content to different types of users. Easy enough. However, the way they distinguish between different types of uses is via the url that is returned by a different site after users log into that site. So for example, when they get to the EE site, their url will be http://mysite.com?eID=IQ00000123456. The last 9 numbers will be unique to each user, and the type of user is determined by the first 2 letters after the = sign—they can either be IQ, MQ, or CQ.
I can have them return the url in any number of ways—it could be http://mysite.com/?eID=IQ00000123456/index.php or http://mysite.com/index.php/?eID=IQ00000123456, for example.
I am at a loss as to how to make this work with EE. Is there a way to ignore a url segment in terms of templating but still grab information from it to serve up conditional content?