Calc lookup

I am trying to find a function in Calc that can do lookup values like in this image:

The function I need should lookup the values in the table like this:

=MY.UNKOWN.FUNCTION(‘2014’;‘APR’;C4:F6)

The formula in D14 should give ‘d’ as result.

I would guess this is possible, but I can not find the correct function.

Thanks for all help!