Solution 1:
Regedit saves last opened key in,
Code:
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Applets\Regedit\LastKey
and restores view to that key on opening.

If you first change value of that particular key and then open regedit, then it will open that particualr key (in Win2K/XP systems).

Solution 2:
http://www.freevbcode.com/ShowCode.asp?ID=7819