consultant to set up OpenX on Wordpress

I have set up open x on my wordpress blog. I need a consultant who can assist me to customize open x. What I need to do is that many visitors to my blog will come in on custom links with parameters - for example [login to view URL] When this person comes in I want one of my ad serving spaces to deliver ads that are specifically tagged with TX. I need to keep costs down on setting this up, so I am hoping to find someone who is already familiar with openx and can advise me on getting this get up.