[cctalk] VMR question for RSX11M and DECnet CEX

I am putting together a PDP-11/23 and have a working RSX-11M 4.4 OS running in simh while I wait for a few parts. I want DECnet as well. I have the 4.7 kit and have done a netgen, but I can't install it because I don't have the CEXPAR partition in my system image. I have gone over the VMR command in the manual a few times and tried various things to try and create the partition in my image, but have not been successful. I assume (from looking in the manuals) that I either need to create that partition in my image, or make room for it? The netgen process has the defaults of 113500 as the base and 4300 as the size. VMR complains about 'non-existing memory' for the base and if I try the wild card I get 'alignment error'. I have 512KW of memory that I plan to use in the real machine, so simh is configured with that as well. Any pointers would be greatly appreciated. -Peter