How do we fit rollerblinds into non-recessed upvc windows?

[WittgensteinsBunny]

Just that really. We have two bedrooms that need blinds. The windows in our house are not in recesses and are replacement sash upvc windows. Is there some sort of mount / bracket that we can use? Fitting into the wall around the window isn't an option.

Have you seen the perfect fit ones that you attach to the window on a frame? You attach the frame between the black sealant and the window.

Like this - Google image search

I have perfect fit blinds - love them

also got perfect fit and they are brilliant