Use the selection tool. Click drag to select the note/chord you want (selecting the chord r4equires that you select the note/rest that it is attached to).
Selecting a note does take some practice to get the selection right. The trick is to start the 'drag' towards the left edge of the notehead/rest and extending the selection to the left edge of the next note/rest.
Once the area is selected, just drag the selection to where you require. This will allow greater precision while pasting
You can also <ctrl>click (I think that the mac equivilent is <cmd>click) the destination measure, but that will always paste to the start of the measure.
One addendum to Darren's instructions: when you click and drag, be sure to start your selection box above or below the staff. If you start clicking on or in the staff, it will be difficult to get what you want.