How to change the seq. dat file for specifying secondary structure?

Hi,

It is my understanding that when you know the secondary structure of the protein, you can specify it by changing the seq.dat file.
The format of my seq. dat file is:
1 CYS 1 8
2 PHE 2 1
3 VAL 2 3
4 TYR 2 4
5 HIS 2 7
6 PHE 2 9
7 ALA 2 9

Would you please comment on how the numbers relate to the secondary structure (i.e. coils, helix, beta strands)?

The seq.ss file is pretty comprehensive but I am not sure if seq.ss is the one which has to be modified!

I greatly appreciate your help.

Regards,
Horia