Yes, something like this.
However, there is the question of how fast you want to move your label towards where the mouse click
took place.
I assume that deltaX = Mx - Lx, where Mx is the x-coordinate of the mouse click and Lx the
x-coordinate of your label (and likewise for deltaY).
In your opening post you had:
meaning that your speed was always 5 units long.
If you want to maintain that speed,
you should determine a factor F
such that the vector (F * deltaX, F * deltaY) has a length of 5.
From the code you showed I gather you know how to do this.
Greetz,
Piet