You probably cannot .ndx files (dBase indexes) to actual .dbf files and here is why. These two files are usually found together and kinda complement each other. A .ndx index contains and maintain pointers to records in the table (.dbf) file and is organized according to the index key values. An index file is separate from but associated with a .dbf file.
So there is really no way to produce a .dbf database just from .ndx index. However, the opposite probably works, you can generate .ndx index from .dbf database.