You could automate Access, but that would mean that Access would need to be
installed on the system where the code runs (which might be the user's PC or
the server, depending on whether your web app is using client-side or
server-side code). If server-side, it would mean an instance of Access being
created for each user, which would not be a good idea on a busy web site.
And then there is the question of where is the data - client side or server
side, same location as the code, or not?

In short, it would probably be a much better idea to add the data-transfer
code to the web app itself rather than trying to use the Access macro - it
will not be any more difficult to do that than it would be to write the code
to automate Access.