s{(\Qhttp://v2vi.click4assistance.co.uk/c4a.aspx?AccNo=Inter12109&IDENT=\E)US}{${1}UK}g

##</code><code>##

s{(\Qhttp://v2vi.click4assistance.co.uk/c4a.aspx?AccNo=Inter12109&amp;IDENT=\E)US}
 {${1}UK}g