Use the leader command.
You can change the size of the arrow if the default is too big or small.
If your arrow end is attached to a line you will get an arrow terminator.
If it's not attached to a line (ie. in 'free space') you will probably get a dot. In this case RMB on the arrow then in Properties you can set the terminator type to arrow.
Alternatively just draw yourself an arrow and make a block.
bc.
2.4GHz Core2 Quad, 4GB RAM,
Quadro FX4600.
Where would we be without sat-nav?