madeinlisboa wrote:
Well I guess it's how it being defined and done so in such a manner that VMware will not work with it.
Well VMware is lame
Before you go making comments such as that maybe it's the RAM Disk Software Manufacture that isn't properly implementing things as necessary or maybe it's something inherently not doable regardless of who's virtualization software is being used! 
but I don't have enough ram to hold a virtual hard disk
What do you mean "but I don't have enough ram to hold a virtual hard disk"? You are/were trying to use the Physical RAM Disk as a Physical Hard Disk in a Virtual Machine, which removes direct access of it from the Host! So I really see no reason why one can't implement an automated solution to have a small virtual hard disk that is stored on a RAM Drive as a part of a the VM to achieve greater speed for the temporary files then having the write to the virtual C: Drive on a Rotational HDD.
Did you not realize that if you could have assigned the RAM Drive as a Physical Drive to the Virtual Machine that it removes direct access of it from the Host or are you not sure how to implement a scripted solution (or both)?