Works for me without a problem.
ALT+Left mouse button to select the objects, btw this doesn't work for actors only for statics, maybe this is the problem.
Then right mouse click save to file.
Then open another mission right click and paste from file, thjen the objects should be at the mouse pointer position.
If you open the saved file with a editor you should look like (example)
Code:
spawn Stationary.Ammo_Vehicles.2cmFlack38_composition1 POSP -0.530 0.636 0.001 POSO -230.000 0.000 0.000 REGIMENT nn EXTPARAMS
spawn Stationary.Environment.SandBagWall_Arch POSP -1.563 1.164 0.000 POSO -210.000 0.000 0.000 REGIMENT nn EXTPARAMS
spawn Stationary.Environment.SandBagWall_Arch POSP -1.153 -1.876 0.000 POSO -135.000 0.000 0.000 REGIMENT nn EXTPARAMS
spawn Stationary.Environment.SandBagWall_Arch POSP 1.247 1.914 0.000 POSO 60.000 0.000 0.000 REGIMENT nn EXTPARAMS
spawn Stationary.Environment.SandBagWall_Arch POSP 1.717 -1.866 0.000 POSO -45.000 0.000 0.000 REGIMENT nn EXTPARAMS
spawn Artillery.20_mm_Flak_38 POSP 0.284 0.030 0.000 POSO -165.000 0.000 0.000 REGIMENT de EXTPARAMS /timeout 0/radius_hide 0
BTW i use a german version of the game so i don't know hows things exactly labeled in an english version. If you don't like my help i put you on my ignore list, so it would not happen again.