First download the latest version on soundforge's page and install it !
Then find the file you want to know informations about and do a right click on it. It will appear something like this :
and when you click on Media Info you get this :
in the view panel, click on custom :
and finally you get informations that are suitable for the forum !
Copy them with the hotkey Ctrl+C (press the C key while holding down the Ctrl key)
Paste them into your message text with the hotkey Ctrl+V (press the V key while holding down the Ctrl key)