If you mean draw them in or create them one by one rather than playing with a MIDI controller, I believe you can absolutely do what you want to do. I don't have Logic in front of me and my desktop is packed up so my answer won't be precise, but try this. Create the instrument track you want to create the notes for.
Now, try Command Option Click, or some combination thereof until you see the pencil tool. Wherever you clicked on your track, you'll now have a blank region. Another way to do this is to option drag another region into that track and erase all info, then you've got a fresh one. Press command 3, and an edit window opens. Next, use that same command as before till you see the pencil tool again. You will be able to draw in volume automation if you're looking at volume, or note information if you're looking at the grid, etc.
Forgive if these aren't precise, I do it so much it's second nature and hard to remember exactly what commands I'm using. You can do this though, and create by step any sequence imaginable. I hope that helps, good luck.