The R4 team have just released a cheat code editor that lets you manage your Action Replay DS cheats. Here's the info from them:
"R4 OS V1.08 from the official version began to point game R4 support functions databases and database users ordinary people support the government, the ordinary people editor for creating and editing user database They support user manual input, also supports the introduction of XML documents."
This could also be used to make the cheat files for NitroHax...