I found this linked on J software's website. There are probably
other ways to call J from a C program documented, but this looks
like a useful framework to deal with returned values from a 
J ticker plant. 

I got the original stuff here:
http://www.ivorykite.com/apl/jx.html

It now builds at least, though I don't think I've quite got the
linking/dependencies right. Untested. 

test change