Install Voice Command 1.5 on your 6700

The attached .cab file needs to be coppied to the 6700 main memory
with ActiveSync (it's inside the zip file)

Install the cab file by clicking on the file.

Reset the device.  

Go to your Windows folder on the PPC, rename the file sddialer.exe to
something like sddialer-orig.exe (in case you want to undo this)

Since  VoiceCommand 1.5 is already on the phone, copy  \program
files\voice command\voicecmd.exe to the \windows directory and rename
it sddialer.exe.

Now, when you hit the answer button on your Bluetooth headset there is
a pause, then you will hear the Voice Command beep in your ear.  To
end the call, press the end button.

This setup also allows you to answer incoming calls.

By the way, I am using a Jabra BT850 headset.  Overall I am pleased
with the results.