Get the StoragePod object from Storage Profiles [vCloud Director]

Hi All

I'm automating some SDRS stuff for the creation of new vApps in vCloud Director and I want to embed and use the Change Storage DRS per virtual machine configuration workflow, but in order to do that I need to supply it with an object of type VC:StoragePod...  I worked out how to get the default storage profile from each VM, but can't figure out how to get to the StoragePod that it relates to.

Don't laugh, but I only managed to get this far before getting stuck:

var vms = vApp.getChildrenVms();for each (var vm in vms) {
 storageProfile = vm.storageProfile;
 ....}

Can someone ideally show me how to get a StoragePod object from a VMs default storage profile? 

Thanks!

Mark