Open the appropriate file for editing:
Personal: HomeDirectory/.dt/dtwmrc
System-wide: /etc/dt/config/language/sys.dtwmrc
For information on creating these files, see Workspace Manager Configuration Files.
Add the button binding to the DtButtonBindings definition.
Do not bind the same button to different functions for the click and press operations, and do not bind more than one function to the same button and context.
Choose Restart Workspace Manager from the Workspace menu.