Hi,
I presume you have a HyperLink tag like this(I do not know your method of dynamically setting it):
<asp:hyperlinkfield datatextfield="LeadID" datanavigateurlfields="LeadID" datanavigateurlformatstring="CurrentPage.aspx?LeadID={0}" ... />
When you click on a particular HyperLink the current page will be displayed. You can use Request.QueryString to have the particular key.
I hope it will help,
Cheers.