If they want large group of volunteers from Balkan you mean? Czechoslovak Army created Velitelstvi cizich dobrovolniku - Command of Foreign Volunteers (under general Miloslav Barta). All tgether Czechoslovak Army had app. 160 000 rifles (mostly A-H origin) ready for volunteers from Czechoslovakia and Foreign. Not only few ten thousands of volunteers from Yugoslavia were expected but there were offer from app. 1000 Americans, British, Belgians, Polish and citizens of other countries (not small amount of volunteers offered their services in Baltic countries. Plenty of Jews were volunteering too. I believe years ago I read something about volunteer from Ethiopia (or was that on some Czech AH forum)
Volunteers were suppose to be concentrated in Are of Eastern Slovakia and Ruthenia.
So there was active preparation to accept foreign volunteers. However higher command would be of Czechoslovak officers. Commanders of platoons and companies could be from volunteers.
Well, in October 1938 the International Brigades were retreated from Spain. Just in time to have a lot of experienced potential volunteers with a desire of revanche against the germans.