Hi Ayan29,
You're in the wrong place, this is the LG/Goldstar forum!
If you turn on call barring under User --> Telephony --> Supervisor Settings --> Outgoing Call Bar then no, I very much doubt your short codes will work. What you would need to do is create a Barred short code (code - ?; telephone number - .). This short code is a catch all, so if you create more specific Dial short codes, those numbers will be allowed (either *8001 or the full number). You can either do this in the User Short Codes for every user that needs it, or in the System Short Codes to apply it to every user, and then take anyone who this shouldn't apply to out of it by giving them a ? . Dial User Short Code, since User Short Codes override System Short Codes.
If you go down the route of barring in the User Short Codes, then technically the *8001 etc. codes will also need to go in the User Short Codes for each user (hopefully you don't have too many?), however you may be able get around it by using wild cards (*8XXX) instead of the full code, and then . in the telephone number field instead of the telephone number, so that hopefully whatever the user dials (*8001 for example) will be matched by the system short codes that you create, but I have a feeling this won't work.
Hope this helps?
Joe Newton
Avaya ACIS (SME), Avaya ACSS (SME), Mitel MCA, CompTIA A+, Cisco CCNA