Unpack ARj-Files

Hello everybody, I need help. Does somebody know how to unpack with C# ARJ-Files? I need to unpack many of them and I have to search for text patterns in those files for informations. Liek Names, dates and so on. The Information I have found I have to store in an ArrayList or something like that. But the problem is to unpack the ARJ-Files. They are all stored in one Folder. Thanks a lot for help. Best. Jo