how to create nuspec file in specific folder?

I tried to create .nuspec file in a different folder by giving path but it is giving me error

Nuget.exe spec ..\MYDEMOFOLDERNuget.exe pack ..\MYDEMOFOLDER\MYPROJECT.csprojpause

want to create MYPROJECT.nuspec in ..\MYDEMOFOLDER folder location

getting error to create nuspec file The package ID '..\MYDEMOFOLDER' contains invalid characters. Examples of valid package IDs include 'MyPackage' and 'MyPackage.Sample'.