[AndMetal]

Here's the code for the wp command:
zone/command.cpp

 2256 void command_wp(Client *c, const Seperator *sep)
 2257 {
 2258 	if (strcasecmp("add",sep->arg[1]) == 0)
 2259 		database.AddWP(c, atoi(sep->arg[2]),atoi(sep->arg[4]), c->GetX(), c->GetY(), c->GetZ(), atoi(sep->arg[3]),zone->GetZoneID());
 2260 	else if (strcasecmp("delete",sep->arg[1]) == 0)
 2261 		database.DeleteWaypoint(c, atoi(sep->arg[2]),atoi(sep->arg[4]),zone->GetZoneID());
 2262 	else
 2263 		c->Message(0,"Usage: #wp add/delete grid_num pause wp_num");
 2264 }

I'm not sure if this will actually work, but you might be able to do something like this:
zone/zonedb.h

	/*
	 * Grids/Paths
	 */
	int32	GetFreeGrid(int16 zoneid);
	void	DeleteGrid(Client *c, int32 sg2, int32 grid_num, bool grid_too,int16 zoneid);
	void	DeleteWaypoint(Client *c, int32 grid_num, int32 wp_num,int16 zoneid);
//	int32	AddWP(Client *c, int32 sg2, int16 grid_num, int8 wp_num, float xpos, float ypos, float zpos, int32 pause, float xpos1, float ypos1, float zpos1, int type1, int type2,int16 zoneid);
	void	AddWP(Client *c, int32 gridid, int32 wpnum, float xpos, float ypos, float zpos, int32 pause, int16 zoneid);
	int32	AddWPForSpawn(Client *c, int32 spawn2id, float xpos, float ypos, float zpos, int32 pause, int type1, int type2, int16 zoneid);
	void	ModifyGrid(Client *c, bool remove, int32 id, int8 type = 0, int8 type2 = 0,int16 zoneid = 0);
	void    ModifyWP(Client *c, int32 grid_id, int32 wp_num, float xpos, float ypos, float zpos, int32 script=0,int16 zoneid =0);
	int8    GetGridType(int32 grid,int32 zoneid);
	int8    GetGridType2(int32 grid, int16 zoneid);
	bool    GetWaypoints(int32 grid, int16 zoneid, int32 num, wplist* wp);
	void	AssignGrid(Client *client, float x, float y, int32 id);
	int		GetHighestGrid(uint32 zoneid);
	int	GetHighestWaypoint(uint32 zoneid, int32 gridid);

zone/waypoints.cpp

int ZoneDatabase::GetHighestWaypoint(uint32 zoneid, int32 gridid) {
	char *query = 0;
	char errbuff[MYSQL_ERRMSG_SIZE];
	MYSQL_RES *result;
	MYSQL_ROW row;
	int res = 0;
	if (RunQuery(query, MakeAnyLenString(&query,
		"SELECT COALESCE(MAX(number), 0) FROM grid_entries WHERE zoneid = %i AND gridid = %i",
		zoneid, gridid),errbuff,&result)) {
		safe_delete_array(query);
		if (mysql_num_rows(result) == 1) {
			row = mysql_fetch_row(result);
			res = atoi( row[0] );
		}
		mysql_free_result(result);
	} else {
		LogFile->write(EQEMuLog::Error, "Error in GetHighestWaypoint query '%s': %s", query, errbuff);
		safe_delete_array(query);
	}

	return(res);
}

zone/command.cpp

void command_wp(Client *c, const Seperator *sep)
{
	if (sep->arg[4] == NULL)
		int wp = database.GetHighestWaypoint(zone->GetZoneID(), atoi(sep->arg[2]));
	else
		int wp = atoi(sep->arg[4]);
	if (strcasecmp("add",sep->arg[1]) == 0)
		database.AddWP(c, atoi(sep->arg[2]),wp, c->GetX(), c->GetY(), c->GetZ(), atoi(sep->arg[3]),zone->GetZoneID());
	else if (strcasecmp("delete",sep->arg[1]) == 0)
		database.DeleteWaypoint(c, atoi(sep->arg[2]),atoi(sep->arg[4]),zone->GetZoneID());
	else
		c->Message(0,"Usage: #wp add/delete grid_num pause wp_num");
}

Hope this helps.