The Dink Network

"I would suggest creating a sprite at those coordinates and using sp_follow(&boss, &sprite);"

A probably better* way is just to move him in the right direction depending on where he is on the screen:

int &x = sp_x(&boss, -1);
int &y = sp_y(&boss, -1);

//might need adjusting if you need him to path around objects:

if (&x < 315)
{
 move_stop(&boss, 6, 315, 1);
}
else
{
 move_stop(&boss, 4, 315, 1);
}

if (&y < 100)
{
 move_stop(&boss, 2, 100, 1);
}
else
{
 move_stop(&boss, 8, 100, 1);
}

//and then if you need it to be exact:
sp_x(&boss, 315);
sp_y(&boss, 100);

Edit: *By better, I mean more accurate. Pillbug's way might look nicer