Hi Dennis,
Few methods available:
1) Store document in blob of HF. Then you can treat like any other record. You'd point to the record, retrieve the binary info and save it out locally and shellexecute.
2) Use windev to create a soap server which has methods that enable you to retrieve and pass it to your app across the net. This could also be written to allow you save the document back.
3) create a virtual directory (or alias) in your web server that points to document storage on your server. Implement some type of authentication on this folder. Then use windev with HttpRequest() to get your document and store it locally.
#3 will be the easiest implement.
Hope this helps.
Cheers!
Ken