You'd be better using MVAM, its designed to move models, so just turn the doors into two seperate models.
You'd need to script the proximity trigger, probably off the Docking Script.
Edit, if you do use the docking script, you'll probably want to turn of the cutscene in the MVAM plugin.
This should produce a nice effect of the doors opening on approach and closing on departure.
Edit 2: Just thought a bit more about this.
If the docking script is used, you could trigger the 'close' cutscene in the MVAM plugin after the docking script is run to show the doors closing after entering.
Similarly, you could use the MVAM 'open' cutscene to open the door before departing.
You'd have to get the timing and the speed of the doors right, but it would look quite cool!
Of course if you don't use the docking script, you'd have to have another way of triggering the doors (via the proximity script you mentioned), but this wouldn't dock your ship obviously.