Pinnacle Studio 9.4.3 only supports opening captured avi, mpg or mp2 video files from the Album interface.

The only way I know of you could do what you are asking with Pinnacle Studio 9.4.3 is to capture the video while the DVD is being played. Once you have the captured video content, you can then edit it as you like. Note that the DVD menus cannot be captured, you will have to build them yourself (this is known as DVD Authoring).

However, if you used a Pinnacle Studio project to burn your DVD, the project is still there after the burn is completed, so you can edit it any way you like, adding more content, or copying parts of it to another project if that is what you need to do. You don't need to capture the video content on the DVD you just burned if you want to use the same project for another DVD.