MIDI echo automation

Dear Sonar users,
 
Is there a way I can automate midi echo parameter for software synth tracks (i.e. from 0.10 till 0.40 the midi signal from the keyboard is routed to synth 1, from 1.00 until 1.20 to synth 2 etc)? I found a workaround by setting midi remote control for each syhth track midi echo parameter and switching it on and off with a separate midi track via loopbe port, but it doesn't look stable. I need something more simple like the automated mute feature.
 
Thanks,
Nick.