Non-"Standard" (A-Z) (0-9) Field Validation

Problem: Suppose I’ve got a lot of international customers and I’m doing E-commerce. I need the ENGLISH version of the address because when I export to CSV, non standard characters do not output correctly when the file is converted from source to CSV…

Recap: I just need to make sure that there are no funky characters; so only A-Z and only 0-9 characters allowed

The brute force method: specify which characters cannot be used, which are very many

Preferable method: if I can make the logic==> “IF => characters are NOT ‘A-Z’ or NOT ‘0-9’” ==> THEN display error message

Is this currently possible and I’ve just been ignorant?