The inscription is:
Karp. Pulk Ulanów
Cairo – Polish Forces M.E.
Sikorski Jerzy (29)

Karpacki Pulk Ulanów (or, more correctly, Pulk Ulanów Karpackich) was Carpathian Mounted Rifles Regiment, part of the Polish Carpathian Brigade that defended Tobruk during late months of 1941. I presume that’s where he earned his Star. I think March 1942 might be rather too early for anyone ex-USSR captivity to earn this decoration.