I was sure I had done this in a blog post recently but it looks like I never posted it so I will post it here and then post it on my blog later in the week. Here is how I would do it if I wanted upper case letters:
[tt]Local NumberVar x:= remainder (PageNumber - 1 , 26) + 1 ;
CHR (x + 64)[/tt]
Replace 64 with 96 if you want lower case letters.
The first line creates the rolling 1 to 26, and the second line converts it into the corresponding letter. I did it in two steps so that I could test the numbers separately and make sure that they were right. Note that the -1/+1 is what makes it roll from 26 to 1, instead of from 25 to 0.
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