Ian – I see the manual states:
Using the included NexRemote software you can control your NexStar telescope with a computer via the RS-232 port located on the computerized hand control and using the RS-232 cable . For information about using NexRemote to control your telescope, refer to the help files located on the disk. In addition to NexRemote, the telescope can be controlled using other popular astronomy software programs.
And Megastar is compatible with the following scopes:
- Meade LX2000, AstroPhysics GTO, Celestron NexStar 5/8/GT/GPS, Sky Commander, NGC-MAX, Sky Wizard, Sky Vector, Advanced AstroMaster, BBox, MicroGuider III, Mel Bartels and RXDesign ServoCAT.
So it should definitely work. Make sure you use the correct driver for the scope and it looks like it all works via ASCOM.