Mixdown with external Synths advice

Mixdown using VST’s only I get…

Using external Synths however…

I have a M-Audio 24/96 so just one Audio In - I therefore feed the output from a real mixer as an input to it so i have multiple tracks of audio coming in on one input so I have to mix them as best I can

Looking for advice on how best to mixdown / export a finished project of Audio tracks (wavs), VST’s & the external synths etc coming in

Do I create a new audio track & record the input from the mixer whilst the VSTS etc are muted? or whole lot together?

Want the output to be one finished audio file (.wav) containing everything

Record external to audio track then export everything.

Thx, so just to confirm:-

mute non external tracks first
record > > >
Results will be saved in the audio track

Then Export all tracks (hoping all in time)?