Creating a flat file?

 Hello

     I am building a flat file using a pl/sql procedure and I need some help with it. The file should have :

1-a header (H)

2 Lines(L)

3- totals(T)

and I have three cursors that return the information and I have built the header with the first cursor and now I need to add the (L) and (T) to this file.
I have used a for loop to create the first part of the file. the file will look like someting this below

H,A,abc corp,012345,refnumber1,amount paid 100.00
L,refnumber1,invno 123,invdate 01/01/2011,paid amount   50.00
L,refenumber1,invno 1234,invdate 02/02/2011,paid amount 50.00