Qt Validator Regular expression

Qt Validator Regular expression

I'm trying to validate entry into a QLineEdit and I have my syntax wrong
somewhere because when I run my program it doesn't allow me to enter
anything in the edit box. The entry needs to be 3 uppercase alphabetic
characters, followed by 1,2 or 3, and then a further 2 digits and then one
final character alphabetic or digit.
QRegExp StudentForm::modCodeFormat("(\\s{3}\\d[123]\\d{2}\\w{1})");