Windows 7 cmd.exe and powershell.exe PATH problems

[Pixima]

I am trying to run powershell.exe in the cmd.exe prompt.
error
The error that comes out is unrecognized command.
I go to System Properties -> Advanced -> Environmental Variables

Under System Variables I find the variable Path.
I add the path where the powershell.exe is.

Shouldn't this solve the problem?
Any suggests?

Thanks

 

[Saltgrass]

You don't want to run it by going to All Programs, Accessories, Windows Power Shell folder?

 

[Pixima]

I don't.

I want to run it within a programming language.

For example, if I call Python's subprocess, I want to run a Powershell command.
I would have to execute 'powershell' before the command is ran.
Powershell would be called in the 'cmd.exe'.