The SQR has a nifty feature called XCtrl that allows you to use normal controller values to access any setting inside the machine, so SYSEX is not necessary. See pp 2-5, 2-6
There is help using SYSEX if you wish to go that route at Royce's website. Get the "SecretBC.pdf" here" http://www.bwalk.com.au/BC2k/BC2k.html
Terry