Sleed BT to Scantool BT, comms.

I'm must starting to make this.

the scan tool uses AT commands and so does the seeed,( CSR chip) how do I keep them from colliding? (or does CSR have hold this config, and go blind command?) I have not read the pdf on CSR yet but will soon. any one see others attempting this? my jpg above should make it clear my project. as does this. http://www.arduino.fixkick.com/hacked.html#MPG

thanks for any pointers in advance, (no code written yet, but soon)