You probably know you can save a remote desktop connection to a file, but have you ever wondered what's in there? Well, just open it up with notepad shall we?
screen mode id:i:1
shell working directory:s:
disable full window drag:i:1
disable menu anims:i:1
The server you are connecting to is set by "full address". Your username and password are set in "username" and "password 51". Please note the password is encrypted for use by the currently logged in user.
With "desktopwidth" and "desktopheight" you can specify the size of the window. You can tweak the RDP session's size to your liking. You can specify the place of the session window on the local screen with "winposstr".
You can find a lot more info here and here.