Hi Mart, sorry to hear this.
"Luer Locks" are mostly used in medicine - so my best guess is actually a pharmacy, doctor's office or hospital if you are looking for a local source.
It might be easier to get an "extension tube" used for infusions, which usually has luer lock male + female on each end... But please don't call an ambulance for that
Otherwise try eBay or just google for "luer adapter male"; I was able to find an adapter made from metal which had a nice M5 thread on the other end - great for mounting by cutting a thread into the tube.
Good luck!
Malte