Our Companies naming policy is to use FirstLetter of Given Name, then surname, e.g. msmith for Mark Smith.

Where there already is an msmith, then we use the First Two letters of Given Name, then surname, e.g. mismith for Michael Smith.

Should we have two Michael Smith in the company, then we continue using letters from the firstname, this time three letters, so it will be  micsmith for  the second Michael Smith. 

So far, at best I seem to only be able to make and use two formats:

FirstLetter of Given Name + Surname

FirstTwoLetters of Given Name + Surname

and set the duplicate detection to use FirstTwoLetters and the template to use FirstLetter by default.

Obviously then it stops there and I'm somewhat worried if there is still an existing user, will it error and not create a user?

Ideally would be nice to have an intelligent option for this "using successive characters of First/Given name", or failing that chain multiple options for Duplicate naming formats to use.

Andrew