I saved the downloaded files into the following:

C:\Users\xxx\Documents\My Games\Order of Battle - WW2\Mods\The Spanish Prelude 0.45a

Thanks to LNDavoust for an excellent campaign. I enjoyed every scenario and will probably play it again some time at the higher Corporal difficulty as I played it on level Captain difficulty. Cheers!

Thanks Gunny, I had fun playing this campaign.