No gimmick - you've hit upon the 1 part of the software that isn't translated. For ordinal rankings: 1st, 2nd, 3rd, etc, English has a pattern that I can follow and compute the proper suffix:
If the number is between 10 and 19 (inclusive), then the suffix is "th"; as in 10th, 11th, 15th, 17th, 19th
Otherwise, if the last number is 1, the suffix is "st"; if the last number is 2, the suffix is "nd"; if the last number is 3, the suffix is "rd"; else the suffix is "th".
I'm certain this is done many different ways in other languages. Maybe with enough information I can figure out a way to make this configurable, but for now I've just resigned myself to the fact that it's going to be in English for everyone. Sorry.