JAR-OPS 1.295:
(b) An operator must select and specify in the operational flight plan a take-off alternate if it would not be possible to return to the aerodrome of departure for meteorological or performance reasons. The take-off alternate shall be located within:
(1) For two-engined aeroplanes, either:
(i) [snip]
(ii) [snip]
(2) Two hours flight time at a one engine-inoperative cruising speed according to the AFM in still air standard conditions based on the actual take-off mass for three and four engined aeroplanes; and
(3) If the AFM does not contain a one engine-inoperative cruising speed, the speed to be used for calculation must be that which is
achieved with the remaining engine(s) set at maximum continuous power.
Hope that's what you wanted.