Darkcoin is now Dash - guide is not rebranded yet ; )
As of v0.11.0, Darkcoin Core client offers KeePass integration. This guide will show you how to configure the association between Darkcoin and KeePass and how to save a Darkcoin wallet passphrase entry in KeePass through the integration. When this is done, KeePass can be used to unlock the wallet.
There is also a video (no sound) of this available here: