You can use the Begin/End Select feature on the Edit menu.
The first time you invoke it, it will remember the position you were at.
When you invoke it again, it will select all text between the beginning point and where you currently are.

A nuance for your situation is that when you are “ending” it, you need to be in column mode at that time. Doing this can be as simple as Alt+leftclick with the mouse at your ending point. You would do that just before invoking Begin/End Select a second time.