Sorry, there is no command.
You need to do some 'awk' programming to either:
1. rearrange the DXF file into layers
where each layer is a different el.
2. reformat the DXF file into GRASS
vector format, including the file
that contains the labels.
3. normal import of the polylines into
vector format,
reformat the DXF file to pull out
the proper el labels into the GRASS
vector label file.
I chose (1.) because the necessary tasks seemed more transparent.
Mike Bender
University of Manitoba