use Your::Module;

open my $arc, 'ftp ftp://some.dot.com/pub/3GB.archive |'
    or die;
local $/ = \65536; ## Could your module handle this?

my $arcObj = Your::Module->new( $arc );

while( my( $name, $dataRef ) = $arcObj->next ) {
    if( $name =~ m[^file(\d+.type)$]
    and $$dataRef =~ m[this|that] 
    ){
        open $out, '>', localtime . $1 or die $!;
        print $out $$dataRef;
        last
    }
}