You could try the ITA matrix thing
ITA once you pick the fare you can click 'show booking details' it will then show you the class under which the trip would be booked. You can also email the result to yourself or your favourite friendly travel agent.
Usually it is the first letter of the code example VKOMBI11 is booked in 'V'.
Not since the
enhancement of Austrian's Air Manager tool I'm afraid, unless anyone knows better?