Please note: if you want to manage Trusted/Intranet site through GPO, end users will be not able to add their sites. I have tested the below ADM and I have given a link for a VB Script. You can use one of them. .
;;;;Add one URL to Intranet Zone and Another Url
To
trusted Site Zone through GPO-ADM
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
CLASS USER ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
CATEGORY !!INTRANET_TRUSTED
;;--------
;; Feature: Intranet trusted
POLICY
"Domaincontosohttp"
KEYNAME
"Software\Microsoft\Windows\CurrentVersion\Internet Settings\ZoneMap\Domains\contoso.com"
EXPLAIN !!ExplainText_ConfigurationMode
VALUENAME
"http"
VALUEON NUMERIC 2
VALUEOFF NUMERIC 0
END POLICY
"Domaincontosohttps"
"https"
"contosoEschttp"
"Software\Microsoft\Windows\CurrentVersion\Internet Settings\ZoneMap\EscDomains\contoso.com"
"contosoEschttps"
END CATEGORY ; INTRANET_TRUSTED
[strings]
INTRANET_TRUSTED=
"Trusted sites for IE"
ExplainText_ConfigurationMode=
"Enable or disable listed servers"
___________________________________________________________________ If you are required the VB Script, find the below link. http://social.technet.microsoft.com/wiki/contents/articles/add-one-url-to-intranet-zone-and-another-url-to-a-trusted-site-zone-through-gpo.aspx
After importing this template into the GPO, all I see is just a blank folder with no settings for IE.
Did you checked "Disabling GPO settings filtering" option. Follow the below link and you will see the settings
www.petri.co.il/adding_new_administrative_templates_to_gpo.htm