Instead of just openning Macromedia Extension Manager (from within Dreamweaver), you can install and package extensions and edit and create Macromedia eXtension Information files with your favorite text editor.
Overview
UI Access
To edit an MXI file:
Choose: Commands > Edit Extension...
To install and/or package an MXP/MXI file:
Choose: Commands > Install/Package Extension...
To create a new MXI file from a template
Choose: Commands > New From Template...
To edit the MXI template
Choose: Commands > Edit Template...
