@odiaz2309 you can check out the different options to use RegEx to identify a string like “S.A.S.” here:
Tools like https://regex101.com/ and https://regexr.com/ would allow you to test and train your RegEx code but also get an explanation about what it is doing. And then (well) googeling often helps. You then might have to check the various quirks of implementing it into KNIME (namely the escape and double escape and when to use what).