I've done it before by editing the sudoers list
WARNING: Be careful with this file. Not following these steps carefully could cause you serious problems
visudo
You'll be using vi... hit the "i" key until you see "INSERT" at the bottom of the terminal widow
navigate the file using the up,down,left,right keys
Find the line that says
Cmnd_Alias DIAL=
and add this entry to the end of the line
,/usr/bin/chestnut-dialer
notice the comma... do not miss the comma... follow the same formatting as the existing text on this line... you're just adding a new entry to this list.
After this, you hit the escape key "Esc" until the "INSERT" goes away
at this point, type this in your keyboard
:qt
that will save the changes and exit.
You can now execute chestnut dialer by calling the sudo command
sudo chestnut-dialer
HTH