Creates an entity by string name, but does not spawn it (see DispatchSpawn). If ForceEdictIndex is not -1, then it will use the edict by that index. If the index is invalid or there is already an edict using that index, it will error out.
int CreateEntityByName(const char classname, int ForceEdictIndex)
Edict index used by the created entity (ignored on Orangebox and above).
Entity index on success, or -1 on failure.
Invalid edict index, or no mod support.