how to do the validation of email id in MFC

BOOL CMailDlg::Validate()  
 {  
 CString m_sFrom;
 CString strRegex;
 System::String strRegex = "^([a-zA-Z0-9_\\-\\.]+)@((\\[[0-9]{1,3}" + "\\.[0-9]{1,3}\\.[0-9]{1,3}\\.)|(([a-zA-Z0-9\\-]+\\" + ".)+))([a-zA-Z]{2,4}|[0-9]{1,3})(\\]?)$";  
 System::Text::RegularExpressions::Regex ^_Regex = gcnew System::Text::RegularExpressions::Regex(strRegex);  
 if (_Regex->IsMatch(m_sFrom))  
 return (true);  
 else 
 return (false);  
 }

error C2653: 'System' : is not a class or namespace name<br />
error C2065: 'String' : undeclared identifier<br />
  missing ';' before identifier 'strRegex'<br />
 error C2110: cannot add two pointers<br />
 error C2653: 'System' : is not a class or namespace name<br />
 error C2065: 'Regex' : undeclared identifier<br />
 error C2065: '_Regex' : undeclared identifier<br />
 error C2065: 'gcnew' : undeclared identifier<br />
 error C2653: 'System' : is not a class or namespace name<br />
 error C2106: '=' : left operand must be l-value<br />
 error C2146: syntax error : missing ';' before identifier 'Regex'<br />
error C2227: left of '->IsMatch' must point to class/struct/union