You could make a *.desktop file with the command, then place the icon in the Unity launcher. Desktop files are located in /usr/share/applications. Here's one I made to launch XP in VMPlayer.
Use this or one of the other *.desktop files in /usr/share/applications as a template for your *.desktop file. If you want the launcher available only to you save the file in ~./local/share/applications. If you want the launcher available for all users save the file to /usr/share/applications. Here's some more information on the command string needed:
:/$ cat /usr/share/applications/vmware-player-xp.desktop
Comment=Run a virtual machine
Exec=/usr/bin/vmplayer /share/vmware/Windows\\ XP\\ Professional/Windows\\ XP\\ Professional.vmx