I don't have version 9, but in version 7 you'd use "Resample" from the "Process" menu to convert to 44.1, then "Bit-Depth Converter" (also in the "Process" menu) to convert to 16-bit.
Be sure to use dither--which should really be the default setting--and don't just use "Save As ..." to save the 44.1/24 file to 16 bits; I'm fairly sure that would truncate the samples.
--best regards