I'm relatively new to DotNetNuke and need to do the following:

I'm porting a web site and application to DNN.

The application is essentially 2 custom forms.  The first needs to retrieve part of the URL, call a remote web service, then generate a custom page based on the results.

Specifically:

1. Parse a URL such as www.mydomain/fred (where "fred" represents one of approx. 5,000 existing unique landing URLs)
2. Take "fred" as the token/ID, then call a remote web service passing "fred" and returning some data specific to "fred" to create a customized landing page.  The landing page will contain a customized form. 
3. The form, when filled out by the user, will be submitted to a 2nd web service for processing.

Could someone provide some guidance on how to approach this?  I've never written a custom DNN module, but assume that is what I have to do.  Also, I need to use the URL convention www.mydomain.com{token} to preserve the approx 5K existing custom URLs.  How do I map those to what DNN needs?  The client has ruled out a URL convention such as www.mydomain.com/clients/fred which I assume would make life easier.  Background: I'm a web developer, and have built 2 sites in DNN but only had to use prebuilt modules.

Thanks in advance.