or download this
perl -E"say '.' x rand(80) . '# test comment' for 1..10" |perl -lpe "
+/\s*#(.*)$|$/ && ( substr( $_, $-[0], length($_) ) = qq{ }x(68 - $-[
+0] + 2) . qq{ #$1} )
...............................................
+ # test comment
...
...............................
+ # test comment
...................................................
+ # test comment
...................................
+ # test comment