SET PLAYER POSITION
SET PLAYER POSITION "player id","time"
Set the playhead position of the currently playing item in the specified player.
For example, SET PLAYER POSITION 2,2:30.5 would have the item in player 2 play from two minutes, 30.5 seconds.
You can also denote time as a number of seconds, for example, SET PLAYER POSITION 1,5 would have the item in player 1 play from five seconds in.