I don't know because I don't know the macro or even maria.h.
What it does is simple.
You enter a text, a palette number a label and a position then the tool displays a line you can copy & paste in your displaylist source.
It looks like this ".byte <label,$60,>label,$f5,$10" for "Hello world", palette 7, adress "label" and postion $10.
Sorry for responding so late but I started looking at 7800 programming again. Just so I'm clear...doesn't this do the same a the XHEADER macro in maria.h?