[development] ASP Integration with Drupal?

A client wants to move an existing site to Drupal. The catch is that the existing site has two pages that are ASP. The ASP pages connect to a 3rd party hosted backoffice package and database. The clients current site is on a dedicated leased Win / IIS / Plesk Control Panel server. The Plesk package provides php 5.2 and MySQL 5 so I do not believe we will have any issues installing and running Drupal on the server. Does anyone know of any development, module, etc. that would allow us to integrate the ASP data into Drupal? Any other gotchas I should be looking for? Thank you all for the work you do and for the Drupal software. Ron D.