Offsetting an object using a point as a direction of offset?

I can easily get a line or polyline to offset using the GetoffsetCurves method and I understand the offset "side" depends on the offset distance being negative or positive but how do you tell it offset to a point for the direction of the offset (like how the standard OFFSET command works)? I'll prompt the user to pick a point on the screen but then how do I pass that info to the GetoffsetCurves method? I'm sure it's quite easy. Any help is greatly appreciated.

Thanks

This thread deals with the same issue:
https://www.theswamp.org/index.php?t...0494#msg370494