If I understand you, you have usb 3 on the front panel of your case, but no usb 3 header on the motherboard to connect it to. Is that right?
Seems quite clear to me that OP has USB2 front panel with USB3 on his motherboard and wants to know if there is a way to upgrade his front ports somehow.
Since USB3 connectors have an extra row of connections deeper in the socket, the upgrade would require changing the whole front port assembly to one with USB3 on it. Unless the case manufacturer makes one available, it would be a DIY job.
It seems you were in my situation year ago. That gamma case is lacking external 3.5 bay.(You can not add internal floppy drive in it). Now one solution is: there are 3.5" USB3 bay for front panel is available in market now a days (Bitfenix certainly have some). If they have 5.25" adaptor also you can have it fixed in your empty dvd drive bay.