MVC :: Putting Asp Page Into Contentplaceholder?

I'm incorporating some parts of an old asp application into a newly written mvc app. In most places I've separated out the data access and business logic into the model, and written new view's and viewmodels on the mvc side, although what I ended up with was not perfect, it works reasonably well.There's one area that's probably a bit too much work to do that. It uses an asp treeview and custom controls, and has lot's of code that just isn't partitioned very well. It's one of those 'well I wouldn't start here' situations, but unfortunately it's the code I have. As an application in it's own right it works well and has done for the past 5 years or so. Although it does want re-writing, that's probably more work than I wanted to do right now if I can get away with it.

The asp pages decend from a custom asp page, which itself decends from asppage and contains a custom DAL. What I'd really like to do, is 'paste' the page produced by this legacy asp page into the 'main' contentplaceholder area on an mvc form. I know I can incorporate standard asp pages into an mvc application, but that isn't what I'm trying to do as I want to use the master page from the mvc application.