Something

$ cat 09stage4
#!/bin/sh
set -e
case $1 in
  '')
  eval "$(debconf-apt-progress --config)"
  "$0" debconf
   ;;
  debconf)
. /usr/share/debconf/confmodule

debconf-apt-progress --start
debconf-apt-progress --from 0 --to 45 -- /bin/tar -C /target -zxvf /cdrom/stage4.tar.gz
debconf-apt-progress --stop
;;
esac