Opening a PDF using URL with VB Script

Hi,
 
I'm trying to open a pdf using URL via OLE Automation. First I tried to following script:
 
Dim doc
Set doc = CreateObject("AcroExch.AvDoc")
doc.Open "{URL_2_PDF}", "My Test PDF"
 
However, I'm getting error all the time. But when I use Acrobat Menu --> Open and enter my URL_2_PDF there, it opens without a problem.
 
Can you please post a sample VB script opening a pdf document given its URL?
 
Thanks,
zieglers
 
P.S. My Acrobat version is 8.