In case my question was not clear enough I would like to add some more details. In the nbx user settings you can specify how to process the call after certain number of rings: should it go to users voicemail box, another extension or external phone number, etc.. I have an external cell phone number specified. My question is: can I change it to voicemail and then back to external phone number when needed using a button(s) on my 3com digital phone?
I will work on bosoxfan's suggestion.
Any other ideas are appreciated.
Thank you.