Increment a Text String (from ABY to ABZ to AZA etc.)

It is sometimes desirable to generate a string analogous to the autonumber, that is, to have a way of "incrementing" a text string. This might be useful if, for instance, you have a database field that (a) is textual, (b) has to be unique, and (c) has to be generated programmatically as you add a new record. The following function accepts a string and returns the one that "comes next", as is illustrated in the following table:

If you pass in	The function will return
ABC	ABD
ABY	ABZ
ABZ	ACA
AZZ	BAA
ZZZ	AAAA

In other words, it will work just as you would expect it to for a numeric argument, incrementing the last position if possible or resetting it to A and incrementing the one to its left. The suggested function is case-insensitive; it will preserve the case used in the original string.

Sample use:

Text1.text = IncrementTextString(Text1.text)