USB pin configuration on the B socket

[The Progen]

Does anyone know what's the exact pin configuration for the USB socket on the VCI-100? I'm thinking of soldering a 4 pin mini XLR socket there. Have already done up the cable and I'm quite sure what I've soldered on the female XLR connector is a mirror image of the pins on the male socket but it doesn't seem to work. Since I only have 4 pins, I've not connected the shield ground. Is this necessary for the USB connection to the VCI-100 to work properly?

When I plugged it in, I got this device is not installed properly message on my Windows 7 Ultimate notebook. Luckily nothing blew and the VCI-100 still works properly with a USB connector into its B socket.

[The Progen]

The reason I'm thinking of doing this is because I'd like to mount guitar quick release studs on the side (with a reinforcing plate running half the width inside) so that I can hang the VCI-100 across my shoulders and play it like a keyboard (sort of) on stage. Wanted a more secure connection which the normal USB connector cannot provide.

[photojojo]

I have no idea, but what about using a midi cable to get more pins.

[The Progen]

There are 5 pin mini XLR connectors. My aim in using a XLR connection is because it can lock so I don't have to worry when I'm prancing about on stage.