FS2002 AFCADs... How are taxiway points refrenced?

OK guys, i'm going to try to make a program that converts old FS2002 AFCAD's into FS2004 AFCAD's.
I have a general idea about how to do it... but there are a few problems, especially with the coordinates. As they seem to be refrenced from something... from which point are they refrenced, and in which units (meters/feet)?
Further: what does the hexadecimal sequence mean in the ParkingSpots section. I've figured the rest out by guessing.
From left to right
X from refrence, Y from refrence, Radius, Heading,
no idea???
761.70 155.40 38.00 139.0 0x0C90008A
I have a general idea about how to do it... but there are a few problems, especially with the coordinates. As they seem to be refrenced from something... from which point are they refrenced, and in which units (meters/feet)?
Further: what does the hexadecimal sequence mean in the ParkingSpots section. I've figured the rest out by guessing.
From left to right
X from refrence, Y from refrence, Radius, Heading,

761.70 155.40 38.00 139.0 0x0C90008A