With VMware you can use the vmrun command to launch commands in Windows from your Mac. However, there is no option to do this in Parallels and so VerySimple Dev blog has a Windows app called DockSync which works with a Parallels shared folder.
DockSync monitors Parallels shared folders for files ending with .task extensions. The .task files contain Windows command line actions. You can script a command via Applescript or Terminal that will output a .task file to the shared folder. The .task file will be picked up by DockSync and executed at the Windows command line.