First things first, they sent 944 people, not 44. Of the 944, 44 were combatants, which is what is expected of a country the size of a city with less than 300,000 people (in 1950).

Although I can't find anything on the other 900, I can tell you what happened to the 44. Since 44 is hardly a fighting force, they were integrated into the Belgian force (the Belgian United Nations Command or BUNC or Brown Berets) and landed in Korea in 1951. Upon arrival, this joint force was added to the US 3rd Infantry division. Of the 44 Luxembourg citizens sent to fight, 17 were wounded and 2 were killed. This joint force was then disbanded in 1955.

http://hendrik.atspace.com/eng/Bunc.html http://www.belgian-volunteercorps-korea.be/ http://www.usfk.mil/usfk/content.united.nations.command.68?AspxAutoDetectCookieSupport=1 http://www.kwva.org/brief_account_of_the_korean_war.htm http://populationpyramid.net/luxembourg/1950/