Thank you for your reply.  It reassured me that I was on the right path. From having read other Help texts, I guessed that I would have to use good ole mail-merge and set up a numbers list in Excel. Luckily my knowledge of Excel was good enough to know about the drag&drop for sequential immediate numbering. When it came to the crunch, it was this particular type of mail merge which gave me a bit of initial difficulty. Despite my having used it happily and often in Word, for labels in Publisher, it was - not surprisingly - different in certain respects; principally the crucial point of the Print stage, which necessitated finding the option Publications & Paper Settings, and selecting 2 specific parameters, namely (1) Multiple pages per sheet,  (2) Single-sided printing (my default double printing had appeared). Once I'd sussed this, it was plain sailing.  Thanks again.
InDesign’s automatic page numbers work well enough, but what about special cases? Some documents require pages to be omitted from total page counts. Other documents use several different systems. Sometimes section numbers or special codes must be included. Well, don’t start typing in those numbers manually, because InDesign can handle it—and quite gracefully, too.
You won’t use any of the standard List Number styles for SEQ field numbering. You need to create your own style if you want correct indentation and alignment with the tab position of the first word after the number. In this example, I’ll create a new style called Step Number, but you can call it whatever you want. In this example, I’ve also used the default settings for tab and hanging indent positions — you can change these later if you want.
Set up a matrix in Excel, one column for each ticket position (stack) and one row for each sheet, plus one for field names. Fill the first column down in consecutive order, then the second, starting where the first column leaves off, and so on. Afet a couple of columns are filled, you can auto fill across the rows, too, so the whole thing takes only a couple of minutes. Name the stacks and use a different field for each position on the page when you do the merge. The trick is to set up using a custom file for the total number of tickets or whatever, divided into the correct number of stacks and sheets. sequentially numbering in coreldraw