adob.stream - open local file ?

Hello all,

I'm using VBScript, an adob.stream object and its "open" method to try to 
access a big*, local file.

* ~ 4GB, which is why I don't want to use loadFromFile.

Alas, no matter if I provide a relative or absolute path to the file, I get 
the same error message every time :

"ADODB.Stream: Arguments are of the wrong type, are out of acceptable range, 
or are in conflict with one another."

I've googled for some example code, but somehow can't find any.

Does anyone know what might be the problem ?

Regards,
Rudy Wieser