It is my mistake. You can read .PFX certicicate as the same way as .CER,
So the Keypoints are.
- .PFX contaning both the key.
- In Order to import and export and read .PFX file from a folder in order to verify sign required "Password" of the .PFX file.
- In order to read .PFX file (Private key) from STORE not required any password.