Combine two intersecting contours into one contour

I am making a font and needs a feature to combine two intersecting contours into one. I wonder whether FCP can do it. Or if FCP can not do it at all, is there any other tools availabel in the market? I need it asap!

For example, I have one curve intersecting one vertical line. I want to combine these two countours into one. Any way to do it?

Thanks,
Sherwood

This is described in the help file and manual (they contain exactly the same content), this is the relevant online section.