File Linking Automation

Hi

I am working on automation of File Linking.
We have files in local folder.
Currently user selects Sales Quotation from overview session, click on Attachment button on the session, answers "File Linking" on the following question, then session dmdoc4540m002 appears.User than fills the details and browse file from the local folder and upload it.

We need to automate it now and run it through job.
The issues I am facing are
1)Can "File Linking" be run as subprocess of Sales Quotation overview session while running through AFS?
2)How to get file from local folder path (eg.C:\upload\<Quotation No>\) and use it in stpapi.put.field( "dmdoc4540m002", "filename", "file_from_local_folder")?As I am not getting any function like dir.open() for local folder

Any suggestions?