Create Fannie Mae 3.2/3.3 format file

Greetings from Cago ! We have a need to generate a .fnm file (Fannie Mae 3.2/3.3 format file) that can be opened in Calyx Point software. Our exact need is to generate the .fnm file, given the loan application fields that will be input by a user on a web interface. Bidders must be familiar with the file format, and preferably have done this task of generating the .fnm file before. If prototypes or sample code is provided, it will be useful.