From today (thanks to Roman for debugging) is now possible to upload my dats via ClrMAME "WWW Mode". Here's how:
1. Start ClrMAME.
2. Click on "Profiler".
3. Click on "WWW Mode".
4. Now click on "Add Site".
5. In field "URL of XML Dat" copy this address "http://www.progettosnaps.net/dats/cmdats/MAME_progetto-SNAPS.zip" and/or "http://www.progettosnaps.net/dats/cmdats/MESS_progetto-SNAPS.zip".
6. In field "Site Alias" write "MAME progetto-SNAPS" and then click on "OK" button.
7. Now you have all of my dats updated to latest version.