Jemand

for cdnr in CD* ; do
        cd "$cdnr"
        cdnum=$(echo $cdnr|sed -e 's/CD //');
        low=$(ls|sed -e 's/.mp3//' -e 's/^0*//'|sort -n|head -1)
        high=$(ls|sed -e 's/.mp3//' -e 's/^0*//'|sort -n|tail -1)
        num=1
        for i in $(seq -w $low $high) ; do
                count=$(echo $num|sed -e 's/^\(.\)$/0\1/')
                mv *$i.mp3 "../Perry Rhodan - Silber Edition 13 - Der Zielstern CD${cdnum} ${count}.mp3"
                num=$(($num+1))
        done
        cd ..
done