Custom Data :: Using PowerShell Cmdlets

I want to send a PowerShell script during an Azure VM creation , which would install chef client in the VM. I can do that using CLI command "--custom-data" . But is there any similar command for PowerShell Cmdlet?.

Also, the custom data gets saved as AzureData.bin file in the VM. When i open the AzureData.bin file in a notepad, i can see my script available. But how can i make this execute automatically during the first boot of the VM. I don't want to login to the VM everytime and run the script manually.

Can anyone please help with your suggestions?

Thanks,

Anish