The idea of using a multi‐Z(e.g., carbon, oxygen) thin plasma column as a medium for soft x‐ray lasing action is presented. A plasma confined by a strong magnetic field is first heated by a CO2laser, and then cools rapidly by radiation losses. This leads to a level population inversion of hydrogen‐like carbon or oxygen ions. Two computational models are presented. One uses given electron temperatureTe(t) evolutions. The other usesTe(t) calculated from an energy balance equation with CO2laser beam power as a parameter. According to calculations, a total gain ofG≳100 is expected for 3→2 andG≳10 for 4→2 transitions (&lgr;=182 A˚ and &lgr;=135 A˚, respectively) for C VI ions using a CO2laser beam with power ∼5×1010W for plasma column heating.