Hi - I am currently without sensible internet access, but I can say in
brief that what you want is certainly do-able, and indeed will not
be very difficult. The first stage you can do already - if you just
play notes in then they are all assigned to the same duration and will
there for the next stage.
The next stage is similar to the Check Pitches mode (play with the
Control key held down) but with registering the time of each note as the
duration to be attached to the note. That will take a few lines of code
- I'll look at it when I can get better access to the internet.