repeat 5 echo "*" $* "*">/tmp/bx$$
/bin/ed - /tmp/bx$$ 
1s/./*/g
2s/[^\*]/ /g
4s/[^\*]/ /g
5s/./*/g
0a

.
1,$p
w /dev/null
q
rm -f /tmp/bx$$ >* /dev/null