Can't find anything about this in the Cisco guides (Administration, Feature nor System guides) nor on Google, so I'm afraid it's just not possible. But...
Does anyone know if it's possible to change the timeout on the CCMadmin page that causes automatic logout on inactivity?
We have a habit of login on in the morning and off when we leave work (locking the PC when we leave the room). Sometimes we leave in the middle of configuration activities, coming back to find us kicked out of the admin webpages... :-%.