multiple parameterd from datagrid

I have a datagrid which has a hyperlink coloumn :

<asp:HyperLinkColumn
DataNavigateUrlField="ACTIONID"
DataNavigateUrlFormatString="admin_editaction.aspx?ACTIONID={0}"
Visible="True"
HeaderText="Details" text="Edit"/>

This all works fine but I also want to send another parameter "StaffFK"
which is in the dataset but not displayed in the grid. I cant figure it out
as there is only one DataNavigateUrlField available.

Can anyone tell me how I go about sending this parameter as well as the
"ACTIONID" you can see above ?.......if possible.
(boy this .net is hard work)

Thanks in Advance