parallels mounter will work only from Mac side.
So to use it, I'd suggest to copy the .hds file to another mac
then rename the extension to .hdd
and then mount using Parallels Mounter (you can use trial copy of Parallels Desktop to install it on another Mac to have Parallels Mounter as its included in the package)
but also it is not clear, why you don't have a .hdd file form the virtual machine bundle. hds is a part of virtual hard drive and it can appear that your particular hds file can't be mounted. so no guarantee here.