I really like the keyboard functionality in YouTrack, but I have yet to find a way to accomplish this.
I create a new swimlane with ctrl+alt+shift+Insert. Then I try to insert a subtask, but neither alt+Insert nor ctrl+alt+Insert inserts task into that swimlane. They just insert into whatever other swimlane has the focus.
On a side note, I also can't seem to understand how to "focus" on a swimlane. The only way I have found that changes focus is to insert a task into that swimlane using the "Add Task" button inside the lane. The swimlane with focus is visually marked, but I can't find a way to click anywhere or use the keyboard to focus on a different swimlane.
Using 4.1.3 #5764.
Create subtask of swimlane using only keyboard