I had the opposite problem ... brought a bed frame over from the US, left the mattress behind (couldn't bear to part from the frame). Could not find a queen sized mattress ... had to buy a 200 x 160 cm. So the next problem was to find a mattress base (or "lattenrost") which would artfully join the two.
In my hunt, I of course found nothing "standard" (no queen sized anythings). However at "Matratze Concord", of which there are several in Munich, they quoted me on making a queen sized bed base specially for me. I'm sure they would make the whole frame if you asked.
For the base, they were going to charge about EUR 200. I assume a frame would be much more. In the end I opted to build my own base ... and being the trial-by-error handyman I am, it ended up costing me about EUR 250 in materials and a weekend, plus a sore back for a few weeks until I had the design right. Should have taken them up.
The moral of the story ... head to
Ikea and buy a whole frame and mattress probably much cheaper. Keep your queen size mattress to throw on the floor at
Oktoberfest time when everyone you know from home rocks up on your doorstep!