If you mean to place your toddler on something so they are off of the floor you can use the 
"one more slot packages' (OMSP) by John Brehaut1 
 here  .  There are several different heights available. For placing sims on the OMSP you will also need the 
magisplay tray  here  because the sim won't snap on to the slots. You need the 
Open For Business EP in order to use the tray in your game. 
Using the cheat 
CONT+SHIFT+C   move_objects on/off and 
CONT+SHIFT+C   boolProp SnapObjectsToGrid true/false. You put the sim on the tray then the tray on the OMSP. You must be careful to remember to remove the sim from the magisplay tray before saving the lot or your sim will be stuck on it or your lot may not load. See this thread/tutorial by HystericalParoxim 
 here . The OMSP and magisplay tray both come with an invisible recolor. I hope this is what you meant.  Good luck with your contest! They are very addictive! :happy8: