Arduino USB Host

I have a project where I need to connect to and control a USB slave device. From a PC, I can use hyperterm or some other method to send Ascii commands to the device. I need to replace the PC with, hopefully, an arduino using a USB Host shield.

Can this be done, all I have read about is communications to keyboards or mice or other interface devices. Some special code around cameras and game controllers.

Any help/direction would be appreciated. THANKS