Switching Channels to change 'solo' to 'tutti'

The challenge here is very basic, I have a string section where the first 16 measures is the principle plays a solo, at which point the section joins him ‘tutti’. I’m using EW Symphonic Orchestra. The violin section is made up of the 18 Violin Master. Needless to say ‘solo’ is not listed in the articulations, so I can’t setup a expression map to handle the switch from ‘solo’ to ‘tutti’. The only solution I can think of would be to setup a ‘solo’ player in a different channel and change channels to get my solo player. Is it possible to change channels (instruments) without have to create a separate staff. Percussion and wind players do this all the time, so there must be a solution out there somewhere.

Thank you for your help.

I’m afraid it’s not currently possible to change channel on a given staff, but it will be possible in the next major version of the software.