What you want cannot be done. Once multiple tracks are mixed together to produce a monaural signal it is impossible to accurately italic un-mix them again. There are some methods for making fake stereo from mono but fake is the operative term. Years ago vinyl LPs were the best thing going. Then came stereo and all the recordpanies wanted to be able to offer stereophonic recordings without having to re-record their entire libraries. One thing they tried which sort-of worked for orchestral music was to just send the lower tones to the left channel and the higher ones to the right (because that is the way most orchestras are seated). Another method which involves a lot of work is to set up a pan pot (sort of like a professional-level balance control) and twist it to place the apparent source where you want it i.e. in a different place for each performer (and don forget where you put them before). There is a method involving peculiar phase shifts which results in something which is obviously not mono but also is pretty obviously not stereo either.