Peter
I have solved it thankyou, I also built a test object. It seems that the placement of SECT_FILL command is important. I was wanting an object with multiple section fills and thought such attributes would be defined with the group data (like the materials) but it seems that it only works if it is defined with the PLACEGROUP command so I have to do a separate solids operation for each different section fill.
GROUP "target1"
BRICK A,B,ZZYZX/2
ENDGROUP
GROUP "target2"
addz zzyzx/2
BRICK A,B,ZZYZX/2
DEL 1
ENDGROUP
GROUP "operator"
add a/3,b/3,-1
BRICK A/3,B/3,ZZYZX+2
DEL 1
ENDGROUP
SECT_FILL "Cut Stone",91,4,8
PLACEGROUP ( SUBGROUP ("target1","operator") )
SECT_FILL "Masonry Block",91,4,8
PLACEGROUP ( SUBGROUP ("target2","operator") )
KILLGROUP "target1"
KILLGROUP "target2"
KILLGROUP "operator"