There are two approaches that I would recommend. I much prefer the first.
First Approach
Project the face to the desired plane. Construct 4 additional planes where each corresponds to one of the four boundary edges of the face. Each of these four planes needs to intersect the first plane along the line that gives you the desired direction of projection. I like this method because it takes full advantage of the projection method.
Second Approach
Use the spp command "by direction". This feature is a little tricky. You need to make a template first to establish a pattern for the projection. I think this approach is overkill.
