int = PosNth(nNth,sSubString,sString)
PosNth(2,'A','Aardvark') = 0
PosNth(2,'a','Aardvark') = 6
PosNth(1,'a','Art') = Pos('a','Art') = 0
Although PosNth(1,sOne,sTwo) is the same as Pos(sOne,sTwo), the former is slower to execute. Always use Pos instead of PosNth if you can.
See also : Pos.