Yep, that's a awning rail...looks perfect to me! We have one just like it and have added a pole awning.
Vintage Looking Awnings
for some ideas, also Awnings
for some detail pictures of the tube that feeds in the rail on ours.
Also, I've added some pictures on our website homepage
that show the awning set-up...if you have any questions or want additional information, feel free to PM or email me ~