Sort of. Mechanical aiming is a system of gears and such operated by wheels and cranks. That's the way the Nebelwerfer worked. Unless you can contrive a motor to take the place of the person turning the crank, there's no making the aiming a remote function. If you have to aim it by hand before walking off with your commo device to fire remotely, you lose some of your advantage - you can only shoot where you've aimed beforehand.
Here's a back image of a Nebelwerfer. If you look closely on the left, below the box the soldier is inspecting, you can see two control wheels controlling mechanical gears that handle the elevation and traverse.
http://www.custermen.com/ItalyWW2/Weapons.htm
On the positive side, I don't think anyone's used that since WW-II.
Here's a back image of a Katyusha launcher. I think it's controlled hydraulically, but contriving a way to do that remotely would take a well-equipped workshop since the controls themselves are levers.
http://en.wikipedia.org/wiki/File:Katyusha_launcher_rear.jpg
Tangential to topic, here's an interesting Youtube link of a Nebelwerfer being fired. Note how the gunners are some distance away, using wires to set it off.
http://www.youtube.com/watch?v=34xz-WPVZqg