crosscompiling a Linux binary on NetBSD

I need to compile a program on my NetBSD boxes that will link against
a Linux library, which is only available in binary form.  I am
guessing that I need to compile the entire program (i.e., my own part
of the code) as a Linux binary, but would welcome information on how
to do otherwise.

In order to build a Linux binary on a NetBSD box, I presume I need to
arrange for gcc to cross-compile somehow.  Does anyone have clear
pointers for how to accomplish that successfully?

Thanks for your help.

Cheers,
Brook