MAP.PTM format

I have to draw a number of pushpins and polylines on a map in order to display where routes go (not with any accuracy just join the dots). AddPolyline is reasonably quick - but AddPushpin is as slow as a slow thing...

Thinking "outside the box" I saved a test (100 "routes" of 100 pushpins with lines inbetween) to map.ptm and opened it in Mappoint. It was instantly displayed (or as near as makes no difference)... this would more than satisfy my boss.

Is it possible to create a MAP.PTM file without using Mappoint and then display it? I guess it must be, but does anyone have any guidelines on the format of the data contained within?

Cheers, and much obliged,
David.

I am not aware of any documentation on the ptm file format or any applications besides MapPoint that can create or manipulate file of this type.. might be a fun project for someone to figure it out.