XHC-WHB04B-6 Macro 10 zum Achse Nullen

Create a new HAL_COMMAND entry in the ini file:
MDI_COMMAND=G10 L20 P0 X0 Y0 Z0

and call that from your hal:
net zero_all => halui.mdi-command-your_number_here <= and2_C.out

Thank you very much for the quick reply!

I had tried to call the MDI commands 
halui.mdi-command-21, 
halui.mdi-command-22, 
halui.mdi-command-23, i.e. to use them again, which did not work.

With a new MDI command, it becomes quite simple.