Find Object of a Type

I'm using the following sourcecode to find an object in an type and update it.

Function UpdateSprite(CurrentSprite,x,y)     
  For Sprite.Sprite = Each Sprite
     If Sprite\Sprite=CurrentSprite Then Exit
  Next
  Sprite\x = x
  Sprite\y = y
End Function

In source from other people I found a function called Object, it looks something like that:

Sprite\Sprite = Object.Sprite(something);

but I didn't find anything in Blitz3D-Helpfile, so I just wondering how this command works.