*DRAIN,Drain __ __ __ > __ __ __ > __ __ > __ __
A,5,-1.5,5,-1.5,5,-1.5[">",STANDARD,S=2,R=0.0,X=-0.75,Y=-0.75],-1.5
Try something alone the lines af the above.
You will most likely need to play with the numbers to get the arrow to line up properly or to get your dashed lines of the lengths you require.
(plus metric or imperial units makes a difference)