Problem outputting data to pedalboard

Hi, everyone.

I'm trying to make a little project which involves controlling a guitar pedal board via an Arduino. Now, the pedal board has a USB input/output which can connect to the computer (and be recognized as a MIDI IN/OUT device) and I can change settings with a handy software, which has a debug option and it'll alert me the message it's sending (And I don't think it's MIDI message, they're way too long).

But I want to change the settings using the Arduino and any sensor (best candidate it's an accelerometer). But first thing I want to test this idea can change at least 1 setting. I have a USB Host Shield which is great to receive input, but I can't find a way to OUTPUT serial data thru the USB. No examples or anything.

Should I just forget about the USB Host Shield? And figure a way to output serial data via the serial port?

Any ideas are greatly appreciated!! Thanks!