The H is your tool length offset(the distance from machine zero to the top of your part with any given tool in Z) The E is your fixture offset(also the same as G54,G55,etc....) So if you wanted to save a x0 y0 position that you are already at you would goto eg
setup-fixture-select fixture and locator diameter-fixture 1 for E1,and 0 for locator diameter- set x and y) then in your program use E1 x0 y0 and it will use what you set and also use H for the tool you set and it will pick-up the tools offset.You do not need D in a drill program, and use a g81 for spot drilling or g83 for peck drilling, then a g80 to cancel drilling operations.
N1 O358 ( DRILL )
N2G20
N3G0G17G40G80G90
N4 ( CENTERDRILL )
N5T1M6
N6G0G90S1200M3E1 X0 Y0
N7H1Z1.M8
N8G81G98X0Y0Z-.1R0.1F4.
N9G80
N10M5M9
N11G90H0Z0.
N12E0X0Y0
N13M30