Is it a way to get system DNS servers as variable in iRule

Hi All,

Is there a way to get system wise DNS servers in iRule as variable? I am asking because I need to target outgoing DNS request to use specific routing domain. thats how I am doing it right now:

[ RESOLV::lookup @1.1.1.1%1 -a "$Origin_FQDN" ]

and I want to replace with system DNS servers. not with hard-coded one inside iRule.

Thank you in advance