my @params = qw(foo too you);
my @values;
push @values,$q->param($_) for @params;
my $line = join ":",@values;
print FILE "$line\n";

##</code><code>##

my @values;
{
    push @values,$q->param($_) for qw(foo too you);
    #set print seperator to ":" just for this block
    local $"=":";
    print FILE "@values\n";
}