Use Set Playback Position to see or set the current position. The position can be absolute from the beginning of the file, or relative depending on mode setting. to change the position.

Modes
Mode Description
Absolute The time entered is the absolute time from the beginning of the file.
Add The time entered is added to the current position. Use this to move the marker ahead a given amout of time.
Subtract The time entered is subtracted from the current position. Use this to move the marker back a given amount of time.