>Thank you Yuri, but it doesn't work (here at least :-)).

Probably you do not have English language on your PC or/and there is another hot key for "preferences" option. Check for proper and exact window title and for proper hot key.

>Anyway, I wouldn't be forced to popup the sys(1037) dialog box.
>I'd like to call the dialog box that appears right clicking on the printer and then on "printing preferences.."

It should not matter what dialog you are using. As soon as you have a Window open and you know the Window title and a hot key, you may use the sendkey method.