Thank you for the reply. After MANY attempts, I figured out through trial and error with the “Rule preview” functionality.
Since you asked, I was trying to extract a date (mm/dd/yyyy) and numeric field (123 or 1,234) from an invoice and then use those two values to rename the pdf file as in "yyyymmdd 123/1,234). The problem I was having was trying to match the pattern of the optional comma when the number reached past 999 (as that’s when the comma started throwing me off). I ended up creating two different rules, one for each case, and that is working for me. Thinking that both rules are XOR (either one or the other will run, but not both) on a given PDF file.
I can only assume that my approach is very “brute force” and that there’s more elegant way to accomplish what I need, but I am satisfied with the results. When I have more time, perhaps I’ll try to find a more efficient solution.
FWIW: I asked same question on the Noddlesoft board and the reply was “For now, you’ll have to use separate patterns to match each case. I’ll consider having options in the future where it can handle thousands separators.”, which I didn’t completely understand but the word “separate patterns” I took to mean separate “rules”, which got me to the solution mentioned above.
Thanks again for your response.