Hi Stefano, if you need a snap point to target the center of an object's bounding box you can create a point object there using the BoundingBoxCenter command:
http://moi3d.com/3.0/docs/moi_command_reference10.htm#boundingboxcenter

It could also be possible to make a plug-in that would move an object by it's bounding box center onto the bounding box center of another object, would that help?

- Michael

Will test that too...re: alignment ideas when I get around to my v4 suggestions or 'wish list' think best I put them on that. Dont want to overload you or say what's 'essential' right now. Really appreciate all the help so far.

[ Reference to script used to import filename to styles, slightly related to this post:

http://moi3d.com/forum/index.php?webtag=MOI&msg=9889.7

Interesting system level way to open dxf files into different views here:

http://moi3d.com/forum/index.php?webtag=MOI&msg=9154.5 ]