Here's a sniplet that does thumbcal... This should set you on the path for the vitos thing too... (never used that...)
Code:
[HKEY_CURRENT_USER\Software\Microsoft\Today\Keys\112]
"Open"="\\Windows\\ThumbCal.lnk"
@="Calendar"
[HKEY_LOCAL_MACHINE\Software\Microsoft\Shell\Rai\:MSCALENDAR]
"0"="Calendar"
"1"="\"\\Windows\\ThumbCal.exe\""
"2"=dword:00000001
"3"=dword:00000000