Yours may not be the same, but my tablet has the same port as the RC does so I can use my tablet USB cable. You can try a local office supply store (if available). Be careful, the port is not really square and some have screwed it up by forcing it in the wrong way.
I must be missing something, but my MP RC has a rectangular charging port on the side, it is not square, and you can only insert the cable one way. You will break something if you force it in the wrong way.
By square, I did mean rectangular. Micro usb cables have a slight curve on one side. Thanks for clarifying. I just am leery about pushing a rounded corner micro usb on a rectangular hole. I will be gentle.