Open file 1 and read file 1 record by record, and:
for (each record) {
    get column D from the record;
    get the interesting part from column D;
    store the interesting part in a hash: some thing like: $hash{interesting part} = 1;
}
close file 1
open file 2 and read file 2 record by record, and:
for (each record) {
    get column D from the record;
    get the interesting part from column D;
    if (exists $hash{interesting part}) {
        print $hash{interesting part};
    }
}
close file 2;