I'm glad it's working for you, it is always nice to see another quality meter jumping up.
First of all I am no expert, so please take the following text as a suggestion if no one else has a better solution. I stand to be corrected anytime.
It is always better to aim at your true south first with your motor.
I haven't had to add birds, but If it is not possible on your receiver, you might be able to do the following:
On my receiver you can edit the existing birds, so you may be able to pick one that is out of range for you and rename it to IA8, change its position to 89 W.
Then edit one of the transponders to the the settings that PSB sugested:
TP. on IA-8 (listed on lyngsat) to use seems to be.....
DFreq. 11780
SR. 29000
Pol. H
This will be only to create a reference for your motor. Once you get good quality on you true south reference bird, the motor does the rest.
If you aim it to a different bird with the motor set at 0, I don't think the motor will follow the arc properly.
Anyways, there isn't much on IA8, so no big loss, but it should be the reference point for the motor as it calculates the position of all other birds based on it.
Once again, this is just an alternate solution, I wouldn't be surprised if there is a much better solution.
Good luck!