Copy group membership of a user to another user

1) Download the VB script from here:
http://www.windowsitpro.com/article/active-directory-service-interfaces-adsi/copy-group-memberships-from-one-ad-user-to-another.aspx

2) Save the script to C drive;

3) Open up an command prompt;
C:\>cscript Copymembership.vbs existingEmployee newEmployee
where ntid1 is the existing employee's username and ntid2 is the new employee's username.