I contacted DA about this last week. I ended up using a USB A (male) to USB mini B (male) cable I had lying around to connect C4 to computer, and ordering a USB host adapter USB A (female) to USB mini B (male) on ebay to connect this cable to the DA DMC4 I have coming. Here's the response from DA:
Hi there! You should be able to use a good quality USB host adapter and the correct cabling. Make sure you update the DMC to the latest firmware version, attached:
Dropbox - DMC_3XL_Gen3_151b.BETA.bin - Simplify your life
Firmware tools are here:
disasterareadesigns.com/files
Once you update you’ll need to set your A device to CBA, at least until we get a working driver for the C4 in the upcoming v1.60. Set USB = HOST, connect the “host” end of the dongle to the DMC and the “device” end to the C4 and you should be good.
Cheers,