Generally your msdn subscription (and everything Microsoft) is linked to your Microsoft account. You can change and or manage account aliases here.
http://windows.microsoft.com/en-us/windows/outlook/add-alias-account
If you meant forums alerts then Quick Access|My Settings
then Configure alerts
Regards, Dave Patrick ....
Microsoft Certified Professional
Microsoft MVP [Windows]
Disclaimer: This posting is provided "AS IS" with no warranties or guarantees , and confers no rights.