You have a bit of researching and stuff to do. This isn't a simple action but a series of actions that all work tohgether like cogs in a mechanical clock - mouse, camera, object, 2d-to-3d translation, orientation etc.
Check out some of the "Level Editor" threads in this (and especially the DarkBasic Pro forum). There's quite a bit to it.
Experiment though - when you start knowing a bit about it - and start asking specifics - our answers will likely help you more and won't require any of us to write a book to try to answer the questions you'll come up with.
this one is to "loaded" for me to even REALLY try. I hope you understand.
If I was you, I'd start with loading a terrain or something... maybe using the built in (advanced) Terrain (Actually fairly easy - just advanced looking) and trying to make a camera fly around.
Check out Sparky's DLL
==============================================================================
~!~ SOFTWARE, ACKNOWLEDGEMENTS, and LINKS
==============================================================================
-The Game Creators - aka TGC - http://www.thegamecreators.com
-DarkGDK - C++ Game Development SDK - http://gdk.thegamecreators.com/
-Dark Physics - aka DP - http://darkphysics.thegamecreators.com/
-Paul Johnson's (Sparky's) Collision DLL - aka Sparky's:
http://forum.thegamecreators.com/?m=forum_view&t=74762&b=5
-Ageia PhysX - aka - http://www.ageia.com
and then you can "Drop" things onto the ground kinda via a simple gravity and using sparky to report when the object has hit the ground for example.
There are more ways than the dropping method - depends what you want this "action" to "feel" like for the user using it.
Post again with a smaller scope question - I'm sure we'll all be glad to help. Somone might even come after me and write a demo of how to do it kinda makign my talk just grovel - but - rthere really is quite a bit stuff in that seemingly simple question you asked.
