Hi there and welcome Ray
Do you mean you want to force the iPad to a particular mode, but allow it to rotate? Sorry it was not exactly clear what you meant.
Double tap the home button to bring up the recents tray. Swipe to the right and you will see the screen icon lock on the left. Unlock it and tap the home button again and you are done.
The screen will then switch based on your orientation.
If you have any problems, or would like any additional information or assistance, please do not hesitate to let me know.
Else if you can take a second to rate my service by clicking one of the stars at the top of the screen then submit, that would be greatly appreciated.