Checking for / Copying a file from external SharePoint site

I'm trying to either check for a file on an external SharePoint folder or ideally copy the file to our network.

I've tried the usual workbook open commands and filecopy commands but nothing is working.

Basically I'd like to check for a new file (the files are normally dated in various formats - I can use the format (now... command)) and download them to our network where the macro can continue with its formatting and file commands.

I can't find any way to open or even check for files on the SharePoint folder. The SharePoint folder has a username and password to enter it.