synchronising tracks

Hi
I have a problem with synchronising wav file audio tracks…before loading to LP16

The LP16 is sold as a 16 channel wav file audio output player that can be connected to a mixing desk for the purposes of independent channel control over e.q, volume etc. for live performances.(A good idea!)
It is obvious that by implication it is clearly possible to record (up to16 tracks), then export from computer, import into Utool then on to the LP16.
What was the design thinking behind this objective and what technical gizmos and programs were used to achieve this?.

So…. Please forgive my ignorance…..
My problem/question is:- What software program is best suited to record my keyboard audio outputs of separated tracks of drums/ bass/ brass etc.(up to 16) ?
I have currently tried recording each single track out from the keyboards into either Cakewalk Gold (a very old basic prog) or into Audacity.
The problem then comes in trying to synchronise these previously recorded tracks to play their respective parts at the appropriate time within the song… For example say: – drums start at bar 1, a bass joins at bar 8, with brass in fills at bar 20.etc etc
Audacity appears to be a painstaking exercise for synchronising and I have never achieved a satisfactory result, even when ‘stretching’ the wave form for more accuracy. Do the tools available within the program appear inadequate?
I did eventually manage to line up all tracks in Cakewalk (by using counter position numbers) however, when trying to export/save from that program, it automatically renders all tracks down to a stereo (two track) output…. which is totally useless to input into the LP16 and defeats the object of multi-track recording!
I would be grateful of any advice on this issue.
Thank you Russ B