How to allow '&' in email address

CRM 3.0 doesn't allow '&' in email address ,however, it's a requirement to make it possible!
The file you need to change is located in: \_forms\controls\INPUT.text.eml.htc,
The idea is change the regular expression for email field:

/*
Allow '&' in email address
Need to edit htc file(HTML Components)
\_forms\controls\INPUT.text.eml.htc 
*/
//var _validEmailRegexp = /^\w([-._'\w]*\w)?@\w([-._\w]*\w)?\.\w+$/;
var _validEmailRegexp = /^\w([&-._'\w]*\w)?@\w([-._\w]*\w)?\.\w+$/;