Hello,
What are you using for the backup process? If you are using something like VCB or VDR you just point it at the vCenter server and it takes care of the rest.
Perhaps if you can detail more of the backup process it would be easier to frame a more complete solution, but here are some thoughts:
If you are using PowerShell it is easy enough to do something like the following:
Connect-ViServer <virtualcenter>
# Find and suspend the VM
$vm = Get-VM <vm name>
$vm = $vm | Suspend-VM -confirm:$false
# The host on which the VM is registered can be found via
$vmhost = $vm.host
$vmhostName = $vmhost.Name
# Do something with your own code.
# Start the VM back up
$vm | Start-VM