I think the idea is to tie in the long branches horizontally onto a framework. You stop the ends, then short vertical flowering shoots should appear each year from the horizontals
have a look at a pruning guide Katarina, it should show a diagram, hope ithelps

Thank you very much, Pam, I know this sort of prunning, but this is for climbing rose, if you want to make it more like a green fence. I wish to have a bush.

I would cut these long shoots back to about 20-40 cm inside the outline of the bush, then pinch the tips when the new growth is about 10 cm long. Watch for new vigorous shoots next summer, and pinch their tips while they are still around 30 cm inside the bush, and pinch again as needed. Be prepared to "brush out" the bush about every 2-3 years, right after the first wave of bloom.

Thank you very much, Tugbrethil, this sounds good.

You're welcome, Katarina.