How will the numbers be entered. I see from your example that there for instance are: 5228001M1 and 4296076M98.

Will there always be either one or two digits after a letter in the end?
Will there always be a capital M there?
Could these values be of a different length than 9 or 10 characters?
If there only is one digit, is 9 one less than 0?

Would be a lot easier if some of these questions were answered.

Regards
-aron