First, do you have a pic or link of which ones these are? I have some ecodes that I'll be putting in my 940T that has stock fogs, and these are a correct fit with the angle and grille etc. Mine have separate low/high/fog, and I am planning my wiring also.
Perhaps yours are the ones that replace the one piece plastic headlight.
If you have a single high/low bulb, aren't you limited to Sylvania silver or something, that cost around $40-50 pr for the bulbs and put out more light? If so I think you're ok with the wiring you have.
In terms of euro DRL, do you mean, you have a two part marker light, one part for turn signal, one part for DRL, no headlight on at all?
Garaget.org (warning; Volvo porn) has a lot of pretty pics of hot Volvos, some with nice light setups. Chrome has a translate function which can be helpful.

http://www.garaget.org/search.php?q=+volvo+740&type=3&p=1&url=http://www.garaget.org/%3Fcar%3D209716%26image%3D1981222