AT commands with usb host shield?

hello,

I’ve got on an internship a Siemens M20 terminal that I can control with a RS-232 port.
Now I have a USB to RS232 cable and the terminal I can also be controlled through my own PC.

I did like that the terminal can be controlled by my Arduino to.

I’ve Used some techniques but with no results, but now I saw the USB Host Shield !

Now my question is can I send through the USB port AT-commands?

mvg tom