hi i have set up a usb ejection one click icon but i want to remove several devices at once EG: E.G.F.I etc: how do i do it

example "C:\Program Files\USB_Disk_Eject.exe" /removeletter H this works for the h drive but i need a few more added to this command string.

they need to be ejected all together when the computer starts.
what is the special syntax symbol i should use to string them in one as in above paragraph.