I think this might do it:
Install Software on a Remote Computer
Description
Installs a hypothetical software program (using a Windows Installer package)
on a remote computer. Requires delegation for the computer and user accounts
involved in the procedure.
Supported Platforms
Windows Server 2003
Yes
Windows XP
Yes
Windows 2000
Yes
Windows NT 4.0
Yes
Windows 98
Yes
Script Code
Const wbemImpersonationLevelDelegate = 4
Set objWbemLocator = CreateObject("WbemScripting.SWbemLocator")
Set objConnection = objwbemLocator.ConnectServer _
("WebServer", "root\cimv2", "fabrikam\administrator", _
"password", , "kerberos:WebServer")
objConnection.Security_.ImpersonationLevel = wbemImpersonationLevelDelegate
Set objSoftware = objConnection.Get("Win32_Product")
errReturn = objSoftware.Install("\\atl-dc-02\scripts\1561_lab.msi",,True)