Right, they would use the tracking code for the heat seeking missile for the direction that the guns would be pointing.

In other words, since the heet seeking missile's tracking code has to make the missile point in the direction of the airplanes, therefore you (theoretically) should be able to take the part of the tracking code that controls the direction that the missiles are pointing in, and apply that to the direction that the blasters are pointing in.  This would make it so that when you "lock on" to the snowspeeders with the blasters, they would always point at the snowspeeder while you are firing. 

The accuracy of the guns couldn't be 100% because that would make it too easy, but it would be cool to be able to track the speeders with the blasters with say, 25-75% accuracy.