If they accept any thing from excelsior like credits for online courses or ECE tests credits (which they usually do) then they should accept Uexcel without any problem, however if you call them right now, they might not even know about Uexcel (excel what?? microsoft ?? ) so expect any type of non-sense answers(ever had those who just google it while on the phone with u and act like they know it since ever ?!) my suggestion for you : go take those tests (its free), once you passed (at least one subject ), have them send a transcript for UoP, at first, my guess is you might have to struggle with them a lil bit (depending on who evaluates your credits) but at the end, you ll be the winner as they wont be able to find a logical reason to refuse it
good luck !!
good luck !!