Well, the Z position should of course be set so that the emblem will actually show up. If you put it in a place where the floor is higher than zero and set the Z position to 0, it will be somewhere below the floor.
Also, please just copy all the lines that you wrote in the MAINCFG (for the emblem). It should look something like this:
EMBLEM 1
X = 5000
Y = -2000
Z = 1024
PLAYERNUM = 0
MAPNUM = 1