Wow that worked perfect, thank you so much!

Meanwhile I created my own solution, but let me tell you how less elegant it is. The cells are not 6 characters, but always 28. In 28 columns I extract the individual characters with the MID command. In 28 more columns I use he EXACT command to get a TRUE or FALSE value depending on if the character is the same or not. In another column I calculate how many TRUE values I have for each row. That's 57 columns instead of your 1!