I know Perl doesn't have an #include directive.
Sure it does. the -P flag to perl runs the code through cpp first. Here's a quick example:
#define CHOICE 1
print "Hey look! I'm",
" using the C preprocessor.\n";
# Here is an example of #include.
my $passwd = <<'-PASSWD-';
print "Here is /etc/passwd: $passwd\n";
note -P can have problems distinguishing between preprocessor directives and perl comments. Also I don't know how well it works on non-Unix platforms where cpp might be missing. All in all it's a poor solution to your problem but it's there if you do need to us it.