[chef] Case statement with wildcards?

[ItsMikeE < >]

I was intending to set up some Chef environments for different parts of the
network but noticed that the information is already present within the FQDN.

Taking the simple example of 
  node1.primary.mycompany.com
  node2.secondary.mycompany.com
  node3.dmz.mycompany.com

how can I write a case statement to process differently according to whether
node is in primary, secondary or dmz?