bool openDBFfile(string filename);

This function opens DBF file. It accepts a string and returns a boolean value, true if everything was good.
Do not forget to close your file if you do not need it anymore.

{
    CDBFapi dbf = new CDBFapi();
    if (!dbf || !dbf.libraryLoaded()) return;

    if (dbf.openDBFfile("c:\\tmp\\example.dbf"))
    {
        // your code
        dbf.closeDBFFile();
    }
    dbf = nil;
}