I don't have a 0.x server but looking at the source code i found online
Have a look at: Tile.cpp
C++:
if(const Monster* monster = creature->getMonster())
{
if(hasFlag(TILESTATE_PROTECTIONZONE))
return RET_NOTPOSSIBLE;
This
may do the job.
C++:
if(hasFlag(TILESTATE_PROTECTIONZONE) && !monster->isPlayerSummon())
If the tile is a PZ and isn't a player summon say "sorry not possible"