Installing a service and modifying settings

I'm trying to install a service with a setup project in VS2005. I have so far successfully made the project install the service with the default settings. What I would like to do though is to collect some information from the user during the install and with that information, modify the application configuration settings I have in the service itself. These are the new .NET 2.0 settings with application scope. Obviously, I need to add a textbox dialog to the install process. My question is how do I write code that uses the output of this dialog, and that can modify the application settings of the service about to be installed?
Any suggestions are welcome.
Brian
[685 byte] By [BrianVallelunga] at [2007-12-16]