VBScript doesn't support the clipboard. Most hosts that host vbscript, such as Internet Explorer give access through the host. Therefore vbscript running in IE or an HTA can use IE's clipboard support. The scripting hosts do not give clipboard support. You can use a vbs file to start IE through COM automation, navigate to a local page (to bypass security warnings), then use IE's clipboard.
Here's a code snippit (Outp. is a text stream)
Set ie = CreateObject("InternetExplorer.Application")
ie.Visible = 0
ie.Navigate2 "C:\Users\David Candy\Desktop\Filter.html"
Do
wscript.sleep 100
Loop until ie.document.readystate = "complete"
txt=ie.document.parentwindow.clipboardData.GetData("TEXT")
ie.quit
If IsNull(txt) = true then
outp.writeline "No text on clipboard"
else
outp.writeline txt
End If