NCF – Extended list of Neutral creatures.

will the advice given by Serovoy help?

It will help. I myself used such a trick when playing through campaigns – I removed all creatures from the generation except for the seven that I needed to upgrade my city. The situation is different if there was an update; then you have to re-edit the text file.
PS: I don't know about the creatures in the Necropolis, but you can find the numbers of standard creatures and much more here. The stalker's number is 138.