What I would do is to use something like CuteFTP to first upload it to my web space. Then tell Auntie to go to the file on the ISP server to either download, or view it.
For example; if your space is something like
w w w . myspace. ispname. co. uk
and your file name:
tell Auntie to go to
w w w . myspace. ispname. co. uk/ video.wmv
(Ignore the added extra spaces in the address; otherwise the PCA site would not show what I mean)