Do this in your code behind:
public string thisUrlFormat = "<a href='http://www.xyz.com/WebForm1.aspx?Name={0}>Click Here</a>";
and when you need to use it in your HTML, do this:
<%=string.Format(thisUrlFormat, PersonName.ToString())%>
If you need to add more parameters, add the appropriate format specifiers to thisUrlFormat after "{0}":
"?AnotherParam={1}"
and change your html to look like this:
<%=string.Format(thisUrlFormat, PersonName.ToString(), 5)%>