Ok in that case my one has the standard bayonet fitting on the wall, from this a standard flexible hose proper cooker one not the silly orange bbq stuff, this is solid fixed to the back of the cooker with a straight threaded connection.
If i was doing this I would take off the orange hose and chuck it, look at the entry point on the oven and measure thread diameter, it will be fairly standard, go to your local plumbers merchant and get black flexible pipe and ask for a fitting to go from that to the oven, get the correct tape/ adhesive for lpg and connect it all up, check very thoroughly for leaks with soapy water.