setting a hyperlinkfield

Im using the dataNavigateUrlFields property of a hyperlinkfield in a gridview to set the link to a field from my database. In my database however I have a folder/folder/filename without the preceding dns.

How do i get .net to go back one folder when it automatically inserts the rest of the url for me?

Usualy you can use a double period to climb up the directory tree, like this for one folder back ../myfile.txt or this for two folders back ../../myfile.txt

Prepend ~/ to the beginning of the string.