Mating a hooked-end tension spring, allowing length to vary

Hello Everyone,

I'm attempting to connect a spring with hooked ends to a flange with a groove on one end, and hook it through a pin with a hole in it on the other end.  The length of the helix part of the spring is undefined, which allows it to vary when I move the handle of the line used for spring length, as long as I'm in the part file or editing the part in the assembly file.  I'm able to mate one end of the spring to the flange groove without a problem, but when I try to attach the other side of the spring through the hole in the pin, the length will not increase/decrease to allow the L-shaped bracket to move along the slot, regardless of whether I attempt to attach it with a mate, or with a sketch relation between the arc used to make the hook and sketch entities in the pin.

I assume that it does not work to do the attachment with a mate since this does not make the spring length dependent on anything other than the arbitrary length to which it is currently set.  I'm also guessing that using sketch relations does not work in this case since the sketch that the spring length is determined in is a different one than the sketch that the hook is created in (the hook is also a child of the helix), so any sketch relations created in the hook are not able to change the helix at all, even though the length of the helix is not defined.

I've watched the How to Animate a Spring video multiple times, and the solution used there doesn't seem to work due to the problems stated above.

Does anyone have any other ideas of how to get the two ends of the spring to both connect to their respective locations while still maintaining the ability to change the length of the spring as the L-shaped bracket moves along its slot?

Thanks

SolidworksAssemblies