Celia, have U called DL? CSRs can see partner award availability which the pitiful delta.com does not show! Air France, KLM, Continental, NW are the most relevant partners.
Where RU flying from? Also, do U know that U can make Paris a Stopover (2ndary destination en route to or from another European city? Where else would U also want to go ?
BTW, it takes more than a few Skymiles: 50K for Y, or 90K for J.