OldPassword As String,
NewPassword As String
[in] String OldPassword
User's old password on a server or domain.
[in] String NewPassword
User's new password on a server or domain.
Changes a user's password from a specified Old Password to a New Password.
A server or domain can be configured to require a user to log on before changing the password on a user account. In that case, only members of the Administrators or Account Operators local group can change the password for another user account. If logging on is not required, a user can change the password for any user account, as long as the user knows the current password.
Dim UserObject As IADsUser
Set UserObject = GetObject("NTDS://YourDomainName/UserName")
UserObject.ChangePassword "OldPassWord", "NewPassword"