Depends what you want.
If you just want the PowerCLI cmdlet, you can do
Add-PSSnapin -Name VMware*
Now you will able to execute all PowerCLI cmdlets (starting with a Connect-VIServer).
The PowerCLI Start menu entry also runs a script, called %programfiles%\VMware\Infrastructure\vSphere PowerCLI\Scripts\Initialize-PowerCLIEnvironment.ps1
This defines some functions and the PowerCLI prompt.
If you want to have these as well, you can execute the script from PS prompt.