Inserting page numbers into your InDesign document is quick and simple. The first thing to realise is that InDesign numbers pages according to the page numbers listed in the Pages Panel (Window > Pages). Unless you want to spend the time manually inserting individual page numbers to override this, you should understand how to define sections in your document (see Step 2, below).

Place the insertion point in the paragraph and choose Restart Numbering from the context menu or choose Type > Bulleted And Numbered Lists > Restart Numbering. In normal lists, this command assigns the number 1 (or letter A) to a paragraph and makes it the first paragraph in a list. In multi-level lists, this command assigns the first lower-level number to a nested paragraph.

I tried very hard to understand your request, but I still don't get it. When exactly do you want that your paragraph restarts at "A"? After a certain paragraph style (title, list or whatever)? In that case, you just need to create a multilevel list. Please be more specific, using screenshot of what you want to achieve at the very end. – Vinny May 18 '17 at 8:17 indesign-numbering