Hello, @zipit! Thanks for your input.
This is a very interesting approach of yours, and I sure do like to learn new stuff. The truth is I didn't phrase my question properly, I'm sorry for the trouble.
I said "keyframe the basecontainer", that's totally wrong, I know. I should have said something like "create a track based on that basecontainer match". In other words, I need to find the whole path back to the object that holds that specific UserData parameter.
I don't think GetClone() will do the trick here. The reason is there's more funcionality that comes from the script's dialog box, things like frame range, frame offset, besides prefix/suffix, custom prefix/suffix, and so on... That's why I've been meaning to create tracks on target Userdata that don't have keyframes yet. By the way, this wouldn't leave Userdata that match and already have tracks out of my target list.
So, I guess, the question remains, is it possible to get a "full name" for Userdata that don't have tracks based on my basecontainer name match? If so, I'd like to create a track for it right away - a simple keyframe with its current value should do. I'm currently looking at DescID here. I can feel the answer is close... all help is appreciated.