Hello, GILLESD, please can make a macro so = Generate groups of four numbers example 12,37,45,89 01 23 46 89 ..... GILLESD, the numbers go from 00 to 99 ok, there can be no repetition of digits, then the 8-digit groups are different, I'll give an example that can not 12,33,46,66 51, this group may not appear in the list, who has a 3.6 digit repeated You can not have, you delete this group Month excel 2010, seven