Help Please......

I downloaded a few AVI files that were split with HJSplit. I am having problems joining them. The first file does not have the 001 extension and the file type does not say 001 File - instead is says AVI file. When I launch HJSplit to join the first file in the folder, it is unable to detect the 001 split files. What must I do or change to the first file in order to join them all.

Any assistance would be appreciated.

Thanx