CCMNo1
You mean you dont know what Excel is like, hav'nt you been watching Trolley Dolleys?? Dont tell them that at the interview.
On a serious note, I had an interview with them a couple of years back (may have changed now but doubt it). Start with introduce person next to you, maths test... which I f***ed up, then they garble on about Excel (try not to fall asleep, probably why I did'nt get the job, nothing to do with the maths test) then interview.
Good luck