scut file joiner
Use this form to join 2 files on a common column and simultaneously extract columns from both files into a common output. The commandline version is much more powerful, but this should make the basics available to you.
The Needle file is typically the shorter file; the Haystack file is the larger file, but there is no functional difference. All of both files will be matched.
The 2 input files have to be PLAIN TEXT, not MS Word or Excel files. The columns should be delimited by TABs or one of the other available delimiters (the commandline version can use any regular expression). The 'Key' columns are the ones that have to match as a basis for extracting more columns from the 2 files. You can extract other columns from each file in any order (but columns from the Needle file will be to the left and Haystack columns will be to the right).