Kind of. You cannot use 3dsemume to do so, it is severely outdated and you should use twloader alongside the bundled ndd bootstrap. You can play through diamond on that without needing a DS cartridge. In addition to this, if you own a legit Pokemon gen 5 cartridge, you can load the diamond save on PC, use twlsavetool to transfer your gen 5 save to your PC, and use melonds to emulate a transfer. Next, just load the save back onto the cartridge with twlsavetool and just use Pokemon transfer. It's long but it works.