Best way to programatically create objects with numeric data attached

[zcrispin0.autodesk]

I have made a script which - in vanilla Autocad - creates a bunch of lines with numeric user xdata attached to them.

I would like to make another script which "exports" such set of lines to map3d, so users can create thematic maps based on the numeric data, and do whatever else map3d allows.

What is the best way to do this?  Or, to break the question down a bit,

How should the lines be represented in map3d, and how should the data be stored? 

1. as object data? 

2. as block data? 

3. as attached data?  (preferably not - this seems ugly having to use excel or suchlike to as well as autocad)

4. or should I just write a shapefile to be read in by map3d?

[Murph_Map]

I would use Object Data to store the data in.