I'm thinking that you have the KDE version of Mint 4.0 and so I am not sure if the application gedit
is there by default.
If it's there then you can use the following. Open a terminal and type:
sudo gedit /etc/resolv.conf
Press enter and it should ask for your password. After you put in your password and return, it should open up a blank text document in gedit. If all that happens with no errors then you're good, close the document ("save" it when it asks) and your resolv.conf file will have been created with the proper permissions. Then you can move on to your next problem with kppp, if any.
(Anyone who has the KDE version, is gedit there? Or should something else like kwrite
be substituted for gedit?)