Use custom variables in your airwave template.
The rough procedure I use for when provisioning this is:
1. Only plugin 1 IAP in the cluster
2. Add the VC to airwave, add the DHCP server address in the Manage page as custom_variable_1
3. have a line like dhcp-server %custom_variable_1% in your template
4. convert the device to management mode and push the template
5. once you get a Good config audit plugin in the other IAPs.