Well, sort of.
Any object can only take position information from one source. Since you've already keyfremed this IK handle it's taking it's position information from the animation curves you created.
Usually for picking things up I parent a locator to the end of the joint and then contrain things off of that locator.
For getting your robotic arm to go to specific 'start' and 'finish' locators I think you're best bet is to key them at those places. This should be easy to do using 'point snap'.
Unless I've misunderstood the problem entirely.