I would probably use map as suggested by toolic.

But you could also use a syntax with a statement modifier:

push @new_array, "<li>$_</li>" for @existing_array;
[download]

Update: This post may seem somewhat useless after the preceding post from the Original Poster, but I had not seen that other post (posted only 3 minutes before) when I wrote mine. I wonder why two monks decided to downvote my post, which was just trying to offer another simplified and, I think, correct syntax, without making any comment. I am not complaining about that, I can perfectly accept that people don't like what I wrote, but I am just wondering why. I would be glad if they would let me know what they did not like in my post.