Custom Configuration for a Phone.

When provisioning phones I would like to have a spot were I could upload a custom config. This config file would override anything specified in the standard provisioning files. My thought would be that you would select "custom" for the configuration type and then the Phone Buttons section would be replaced by a config file editing window that would link to a MAC.cfg file located either in the root of the provisioning directory or in a sub directory called "custom". The file would automatically be generated based on the current configuration settings for the type of phone and then you could customize it for what you would like. When you provision the phone it would simply copy the MAC.cfg file to the configuration directory.