Well,
there are many links can tell you how to add user control at runtime, here is one:
http://www.beansoftware.com/ASP.NET-Tutorials/Controls-Run-Time.aspx[
^]
if the above link doesn't help you google for "add user control at runtime asp.net" you will find thousands of links.
For condition logic you can simply put If...usertype==Admin kind of code and take action to add or not to add the user control.
Thanks,
Hemant