This is great, thanks!
I had to do some slight modifications to make it work with my locale (24h clock and DD.MM.YYYY date format):
For /f "tokens=1-3 delims=. " %%a in ('date /t') do (set mydate=%%c-%%b-%%a)
For /f "tokens=1-2 delims=/:/ " %%a in ('time /t') do (set mytime=%%a-%%b)
set mytime=%mytime: =%
rem echo %mydate%--%mytime%
XCopy %1 %2%mydate%--%mytime% /E/H/I