Looping vm machines and doing file operations

Hi,

I'm using with vSphere Guest SDK Documentation in .NET C#. VI-ToolKit.

I'm  trying to loop all my vm machines in my ESXi and to do some file  operations , I'm confused but I didn't find how I can loop all machines  and use file manager object, there are lot of examples using  virtual machine object inherited from entity object. No file operation  with those object.

I know VIX+VI where combind in the last SDK release.

For Example : How do I create a StartProgramInGuest method in my code?

any suggestions ?

Thanks In Advanced.