EHP4 Portal 7.1 - Store documents uploaded by user from portal

Hi all,

My requirement is to store scanned documents uploaded by users from a portal specific application (WDA), like in travel management.

I can't find any good tutorial or step-by-step procedure which would guide me to one of the following solution : DMS, Archive Link, GOS...

I just want to find the basic customizing steps(excluding admin tasks) to be performed, and the function modules or class that can be used in a specific development.

I have an example in EHP6, but my platform is EHP4 and the class (cl_fitv_gos) didn't have the corresponding method(save_arl_doc) in that version.

Has anyone already done this ?

Thanks in advance for your answers.

Guillaume