Is it possible for any point-n-shoot? In theory, yes. But if you look at the topic, you will find that folks writing CHDK had to get started by debugging with only one LED as feedback. It took many hours to figure out the first thing. It took hundreds of hours to figure out enough to know that they could even do what they wanted.
CHDK exists because (a) it was possible with huge amounts of work and (b) there are tons of Canon point-n-shoots so there is a reasonably large possible audience to support the authors.
So in practice, you need a new camera. I recommend buying one that has the controls you like, but if you can't find one you like, get a Canon that can run CHDK. I'd rather find one that works the way I want from the factory.