Okay... Found out from Vendor that they are going to control these in "5 channel mode" This means that each 6 cell strip will be 5 DMX channels.
I can't change this to 30 channel mode because it is a co-headline tour and the other LD wants them in this other mode. No big deal, I'm just using PixelMad to simplify things. Is this the right editing to make this fixture right?

</Fixture>

<Fixture menuname="martin RGBAW" uniqueid="MAR6" excelexportid="MAR6" pixelwidth="6" pixelheight="1" output="CUSTOM" comment="Martin RGBAW" channelcount="5" channelsperpixel="1" orientation="TOPLEFT">
<channel index="1" output="RED" />
<channel index="2" output="GREEN" />
<channel index="3" output="BLUE" />
<channel index="4" fixedoutput="0" />
<channel index="5" fixedoutput="0" />
</Fixture>
Thanks!
Robb