Hi @FrankColumbo , you may be interested in the following thread
As you have alluded to, this component makes use of java snippet to perform elements of filtering of strings and may give some inspiration. I don’t think you’ll find a “standard nodes” solution to what you are trying to do, or if you do, it’ll probably be so convoluted you’ll wish you’d just written it in java 
By all means open it up and take a look inside! 
Using regex with unicode character classes rather than the specific ascii character subset is probably the way to go for things like “UKEULetters” and so forth.
hope that helps.