bash - Finding lines not starting the same, and editing those. (sed/vim) - Ask Ubuntu

i find lines start number 1 5 not start same pattern other line. then, put * in beginning of lines. there way in vim, sed, or maybe other options?

thanks in advance!

the following command in vim has been asked:

:8,$s/^\([1-5].*\t\)\(.*\n[^\1].*\)/\*\1\2/g