Changing the query form reference on aspx pages in C#

[sumitd]

Hi All

I have a collection of pages where in each page I need to replace the reference of a control with some
other control....
Following is the line of code that I need to replace on every aspx page and there are about 90 + pages :
<%@ Register Src="../Application_Controls/Nonterm_Controls/CommonBookingEngineNonterm.ascx".

How can this be done programatically.Any help will be appreciated...

Thanks in Advance
Sumit