Wow, that takes some nerve coming into a products user forum asking how to abandon it for the competition... You don't really expect to get help now, do you?! (Just kidding, sort of! 
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I've done VHD2VMDK and never had the need to do VMDK2VHD although I'd suspect the steps would be similar. This could be broken down into two separate areas, the virtual disk format and the virtual hardware layer used by the Guest OS. There are free utilities that easily handle the first part, StarWind V2V Converter comes to mind, however since I prefer to use VMware, Parallels and VirtualBox over what Microsoft has to offer I will not address the second part although I'm sure if you Google it you'll find the answer.