You have a couple of options.

First you could use your existing code and "grep" out the ones you want. Example:

my @files = grep(/xxxx\w+/,readdir(DIR));
[download]

Second, you could use a glob function to grab them. Example:

my $dir = "c:\\temp";
my @files = <$dir\\xxxx*.*>;
[download]

~CubicSpline
"No one tosses a Dwarf!"