network - How to populate From Node and To Node fields for a polyline feature class? (ArcGIS 10)

I need to populate FNODE and TNODE fields for my roads dataset. I have an intersections point feature class that has unique ids, and I need each road segment to have an FNODE and TNODE value that corresponds to the intersection id. The roads are broken into segments at each intersection so that each segment only touches 2 intersection points. I thought that maybe Network Analyst generated these, but it doesn't look like it actually writes these values. Does anyone know how to generate these?

This dataset won't be used in Network Analyst - it will be used in a custom legacy add in that a client uses.