I think I understand what you mean. This "may" help or be relevant to what you want:
Add the Touch element to your Layout then in the Event sheet:
On Touched Sprite (Object you touched) > (Object you touched) Spawn Another Object (Line you want to use).
On Touched Sprite (Line) > Set angle towards position (Line.X, Line.Y).
This should set the angle of the sprite spawned towards the position of the line as you drag it.
If you'd like to touch once and then the sprite gets attached to the touch of your finger and move around, I believe you'll need an Every Tick event and a variable.
There is a .capx file attached for you to take a look at but uses mouse instead of Touch. I believe you'd be able to tailor it to your need.
Hope that helps.