It can be done... here's an example (win32 system):

use File::Spec;

my $file;
my $dir;
my $wholefile;

$dir = "c:\\perl\\bin\\";
$file = "perldoc.bat";

$wholefile = File::Spec->catfile($dir,$file);
print "file: " .$wholefile;
[download]

You may want to read the documents again... as well as search Google.

Update: Eep, I must be on a roll today... anyways.. VSarkiss has answered it a bit more concisely!