Angela, would you have any picture of the award? There is NO gold star BUT a Vermeil one for the citation à l'ordre du Corps d'Armée. Wouldn't it be that??
Your question is good and technically interesting. Obviously, it seems that the citations awarded by the commanding officers or higher ranks to NCOs and below are determined by the rank and level of the authority who has decided to give the award: this will determine if the recipient gets the Corps, division, brigade or regiment citation. The final approval is given by the Commanding Brigadier general (when on the battlefield) or Minister of War (for personel belonging to his Department).
Initially, before the Croix was awarded, officers gave oral "citations à l'ordre du jour", which means an officer would recognize the bravery of a soldier for an action he did one day. Not only a soldier could be awarded the Croix de Guerre (and later other medals), but a regiment could too and...in 1917 Dunkerque was the very first town to be awarded the croix. It was awarded another during WWII after the events we know. The total number of recipients of the Croix de Guerre 1914-1918 : 2 065 000
A bill was passed to introduce a "Special Croix de Guerre" which would only award soldiers fighting on the frontline/battlefield, as the French authorities concsidered that too many Croix de Guerre had been awarded. This Bill was never put into pratice.
Here are the scans of the paper given to my grandfather when was awarded the Croix de Guerre (twice) during WWII: once with "Army Citation" (silver palm) and once with "division citation" (silver star). The first one for escaping a POW camp in Germany in January 1945, the second one for his beahaviour and acts during the Brittany Battle in June 1944.
I enclosed a translation of the second page which states why he was awarded the Croix de Guerre with "Army Citation" (He was a senior NCO in the French SAS, Motor Squadron):NCO parachutist with the highest courage and devotion. Already cited for his brilliant conduct during the airborne operations in Brittany,
[That's why he was awarded the Croix de Guerre with Silver star peviously] and after showing daring and calm during the Sud Loire combats, proved on January 2nd at Wavreilles (Belgium) his undertaking spirit and courage during a dangerous Recce mission.
Entering foolhardly in a heavily defended village hold by a German motorized company, he was taken prisonner after being wounded. The enemy, surpirzed by his audace and courage, suddenly decided to withdraw after they interrogated him. Though wounded, has tried several times to escape.