I've looked at several Java regex tutorials, but haven't found a way to
do:

!regexString.equals(inputString);

using only regular expressions. I see that [^X] will return true for
any character that is not X, but what if I want the string that is not
"XYZ"? Entering [^XYZ] or [^(XYZ)] return true for any character that
is not X, Y, OR Z rather than any string that is not XYZ together. I
hope I've explained this clearly. Can anyone tell me how to use Java
regex for !String rather than !character?

Thanks