Hi bilboy,
I did find something thats working, it looks very ugly formula though :(
=IF(IFERROR(IF(VLOOKUP(LEFT(B9,1),_S1,1,0)=LEFT(B9,1),VLOOKUP(MID(B9,2,LEN(B9))/1,_p1,1,0),IF(VLOOKUP(LEFT(B9,1),_s2,1,0)=LEFT(B9,1),VLOOKUP(MID(B9,2,LEN(B9))/1,_p2,1,0),NA())),"")="","",B9)
Take a look at...