You can modify general properties (such as the title) and the contents of the built-in subpanels.
Create a new Front Panel configuration file:
System-wide: /etc/dt/appconfig/types/language/name.fp
Personal: HomeDirectory/.dt/types/name.fp.
Copy the entire default SUBPANEL definition from /usr/dt/appconfig/types/language/dtwm.fp to the new file:
	SUBPANEL   subpanel_name
 	{
  	 …
 	}
Modify the subpanel definition.
Save the new configuration file.
Choose Restart Workspace Manager from the Workspace menu.
For example, the following definition, placed in the file /users/janice/.dt/types/PerApps.fp, changes the name of the Personal Applications subpanel:
SUBPANEL PersAppsSubpanel
 {
 	CONTAINER_NAME					TextEditor
 	TITLE								Janice's Applications
 }
Create a Front Panel configuration file /etc/dt/appconfig/types/language/name.fp.
Define the system-wide control in the file.
Use the CONTAINER_NAME and CONTAINER_TYPE fields to specify the container for the control:
	CONTROL control_name
 	{
 		CONTAINER_NAME					subpanel_name
 		CONTAINER_TYPE					SUBPANEL
 		…
 	}
Save the configuration file.
Choose Restart Workspace Manager from the Workspace menu.
For example, the following control defined in a new file /etc/dt/appconfig/types/language/DigitalClock.fp adds the DigitalClock (in the Desktop_Tools application group) to the Personal Applications subpanel for all users.
CONTROL DigitalClockControl
 {
 	TYPE						icon
 	CONTAINER_NAME			PersAppsSubpanel
 	CONTAINER_TYPE			SUBPANEL
 	ICON						Dtdgclk
 	PUSH_ACTION				DigitalClock
 	PUSH_RECALL				True
 }
Use the same procedure as for removing a Main Panel control. See To Remove a Control.
Add the following field to the subpanel definition:
CONTROL_INSTALL False