Ok, assuming that with “don’t know how to select it” you mean “don’t know how to select it without a input device connected”, correct? (Can’t you just shortly connect a USB keyboard till you have your remote control activated?_
As you are able to SSH into the device there is most likely a way to copy a respective keymaps file into the folder.
But my lazy path would be that you install vnc [HowTo] Install a vnc server on the Raspberry pi
That would give you the ability to remotely control OSMC to activate the remote as described by DBMandrake.