A saddle for my house

I have three 75mm round steel posts between which I am going to put pool-style alum. fencing, but I have a little problem. The shrouds available for pool fencing are flat and are designed for flat posts :( Has anybody in their travels seen shrouds for round posts?
I thought of fitting saddles to the post that would give me a flat area to screw the shoud to, but then I need to either fabricate them or find a supplier. The flat surface would have to be about 60x40.
Its in a highly visible position so the solution needs to be attractive.

Hope someone can help me out...
Cheers
Michael