I am trying to write a batch process to take all the videos in a predetermined folder and merge them with another video.

Here's an example of what I am talking about:
copy /b [path]\[intro1] + [path]\[base video1] [path]\[joined video]
copy /b [path]\[intro1] + [path]\[base video2] [path]\[joined video2]

So say I have 5 intro videos and 5 base videos and I run the process it will output 25 videos. It will not always be that number though. And it is too time consuming to have to constantly rename these files every time i want to merge them. It is also important that the joined video file name would be intro1basevideo1.[file extention]

Thank you so much for your time!
Mike