Identification of a Company / Bataillon? Which Army Group?

[Hugueso]

Hello,

This is the address of a letter sent to one member of my family by his sister. The soldier was Emile Reicher, a French 18 years old young man, forced to join teh German Army because he was born in Mosel, France.

The address is :
Grenadier REICHER Emile
1 Komp. Ers. Bat. 309
Ruhleben Alex Kaserne
Berlin Spandau

Can someone help me and tell or explain me if I can retrieve the name of the unit, division, Army, he served in?

He died in Kirovograd, december 9th, 1943.

Thank you for your help.