if %date% is 30/06/2012 and you want 30.06.2012 then
set today=%date:/=.%
echo %today%
30.06.2012
or if you want yyyy, mm, dd in variables then
set yyyy=%date:~0,4%
set mm=%date:~5,2%
set dd=%date:~8,2%
set today=%yyyy%.%mm%.%dd%
the above will work if the %date% variable is always in that format (yyyyy/mm/dd)
it gets more complicated if you want code to handle any common format
it gets more complicated if you (or your user) does not have admin access to the registry
I have the batch code done to do all this if anyone is interested