tabs in @F @Verbatim include

[slomium]

When I include a file like this:

@F @address@hidden"s:/safe/bin/do_ailhm"}}

I get an error like this:

8,1: character "\011" replaced by space (it has no glyph in font Courier Base)

Which I think is possibly influenced by the following line in the file 
lout-3.29/font/Cr.

C -1 ; WX 600 ; N tab ; B 19 0 581 562 ;

Is there a way that I can get, say, 4 spaces for every tab?  Can I modify the 
font metric file to do this (perhaps by defining a very wide character as a 
tab), or is there a way in lout to specify something other than 1 space as a 
replacement for the tab?

Thanks,
Dave