There are a lot of ways to automate IE, but if you are just grabbing the HTML and saving it, you'll be writing a lot more code to do it.

Try LWP::Simple:

use LWP::Simple;
my $url = $ARGV[0];
my $file = "c:\Documents\savefile.htm";
getstore($url,$file);
[download]

Can't get much easier than that!