Specialized Roubaix - 2007

the plastic cable guide under the bottom bracket is held in place by a screw

the screw looks fine, but it doesn't hold anymore - it seems like whatever threaded fitting was in the frame for the screw to screw into is now stripped.

is there a fitting?

if there is a fitting, could it have popped into the BB cavity?

or maybe the carbon frame itself was threaded..?

when I took the screw out, there was a lot of white powder, like when something aluminum oxidizes - again, the frame is carbon, and the screw is still threaded, making me think there was some kind of nut...

any ideas?

I searched, and read that i could superglue the guide in place, but i'd rather not do that.

thanks.