I've added a JTextField to the center pane. Above that I added a JLabel to identify it obviously, but it's on the far left side.
To me this indicates you are using a BorderLayout. If so, then the following should work:
However, since you say it doesn't work, then you can't be using a BorderLayout. This means we don't have enough information to solve the problem. As Maneesh has pointed out position can be controlled by the layout managers and by the painting of the component itself.
Post your
SSCCE to demonstrate the problem so we don't have to guess what you are really doing.