Subject: How to calculate point of intersection of ecliptic with horizon?

To expand, I would like a formula/algorithm for calculating the point 
of intersection of the ecliptic with the local horizon for any given 
date or place, preferably in units of ecliptic longitude (lambda). 
Does a relatively straightforward algorithm exist for this problem? 

I have programming skills and a library of basic astronomical 
procedures for conversion between the various coordinate systems in 
use.

Re: How to calculate point of intersection of ecliptic with horizon?