actualy for AI there is not one... i believe though that in your standard dark basic pro commands you have something that allows you to select the objects. In fact it was in the 5.8 examples.
I will be back with the command.
EDIT
Here ya go
PICK OBJECT
This command will return the Object Number of the closest object at the specified screen coordinates. The objects that are tested
against the 2D coordinate are only those within the Object Start and Object End range in order to speed up specific tests. If no object
exists at the coordinate, a value of zero is returned. If an object number is returned, additional data will be generated and stored
internally. This extra data can be retrieved using the GET PICK VECTOR and GET PICK DISTANCE commands. Be aware that there may
be multiple cameras when picking objects. To make sure you are selecting the correct screen object, use the SET CURRENT CAMERA
command for the screen being rendered by that camera view. Do not use extreme camera range or object distances with this command,
as this increases the inaccuracy of the raycast line being used internally. You can specify an optional parameter to ignore the camera
orientation, which is usefulfor selecting objects that also ignore the influences of the camera.
Syntax
Return Integer=PICK OBJECT(Screen X, Screen Y, Object Start, Object End)
Return Integer=PICK OBJECT(Screen X, Screen Y, Object Start, Object End, Ignore Camera)