Hi Harvey.
The feature you are looking for will be in the next release of DashBoard. Instead of using an <ext/> tag (external link), you will want to use the updated <exit/> tag and specify the "openpanelid" attribute:
<exit level="panel" openobjectid="PANEL TO OPEN" prompt="Exit?" name="Launch Other Panel"/>
We don't presently have a beta available - the <exit/> tag with a level of "panel" is in the current version but the support for "openobjectid" will not be available until 8.6.
James
#DashBoard