This is screenshot from my Vista Bar but it should be the same for XP.
Right click on the toolbar and uncheck “lock the toolbar”.
Then carefully move your cursor down near the last icon showing until a double arrow is displayed. You can then drag the arrow to the right to make more room for other icons. You should then be able to drag and drop the various icons around to the order that you wish.
When satisfied, right click and check “lock the toolbar”.