1) Learn a few signals from the original remote into your Pronto.

2) Use DecodeIr with either DecodeCCF or IrTool to decode those signals.
[Link: hifi-remote.com]
[Link: hifi-remote.com]
[Link: remotecentral.com]

3) Look up those decodes in the web site of Sony IR codes at
[Link: hifi-remote.com]

4) Use MakeHex with either IrPanels or Hex2CCF to produce the full set of 128 possible signals for any Sony protocol and device number you get from step 2 (or which step 3 tells you is related to the ones you got in step 2).
[Link: hifi-remote.com]
[Link: remotecentral.com]
[Link: remotecentral.com]

5) Find signals that you want, that aren't on your original remote, in the tables found in step 3. Test them with the CCF files produced in step 4. Maybe test all 128 buttons of each CCF produced in step 4.

6) Ask in more detail if you have a problem with any of those steps. Report results back here, so others who search this forum for the DA3300ES will benefit from your efforts. If you find function that aren't included in the tables found in step 3 (by decoding in step 2 or by testing all 128 functions in step 5) please email them to the maintainer of that site ( [Link: hifi-remote.com] ).