Just use...

print "\r 10% complete (or whatever)";
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Which will return to the left of the screen before printing. As long as you don't print past the screen width you'll be okay. You can get the screen width using

use Term::ReadKey;
my ($wchar, $hchar, $wpixels, $hpixels) = GetTerminalSize();
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which would allow you resize the progress bar on the fly.