vbscript calling ActiveX(MFC) control method fail

I have created a simple ActiveX control using MFC wizzard and add
a simple method "testdlg" to show a test messagebox.
Insert this control into a html using <object></object> tags, then using vbscript "obj.testdlg" to call the method, it does work and show the test messagebox.
But when I use these vbscript code without <object></object> tags
"
Dim obj
Set obj = CreateObject("progid")
obj.testdlg
"
it doesn't work.
What's more, I have tried these code in VB, it can also work.
I have to use the ActiveX control in a scripting environment
which only supports vbscript (exclude html).
So can anyone handle this problem?
I really appreciate for your help!

Maybe there is the similar problem in the following thread

http://www.dev-archive.com/forum/showthread.php?t=252894

but no one reply:(
[908 byte] By [theshuttle] at [2007-11-19 7:06:38]