This works on unix and windows
in reply to SOLVED - TK: How to change color of readonly BrowseEntry
UPDATE: You found the answer before me.
my $update = "hello";
my $bb = $mw->BrowseEntry( -variable => \$update,
$bb->insert( 'end', qw(one two three) );
PS: I got the answer from the CPAN description of Entry (which is a sub-widget of browse entry)