Will do... I tried your terminal command using

defaults write com.vmware.fusion.plist powerOnAtStartup.cfg -array "/Users/Karl/Documents/Virtual Machines.localized/Work VM Fusion 4.vmwarevm/Windows 7 (external).vmx"

But I get this: Could not parse: /Users/Karl/Documents/Virtual Machines.localized/Work VM Fusion 4.vmwarevm/Windows 7 (external).vmx.  Try single-quoting it.

Thanks for your help.