CC Dreamweaver Regular Expression Problem

I need to search and replace this phrase "http://cl.exct.net/?qs=bce38cfd33329019b3586d9543709eaf3e2e7782f06d48a901169a2bc1f42daeaab67258f1fe77e788419dc2a282f5e8" in CC Dreamweaver. after qs= those values will change.

this is it in context

<td align="right" style="color: #6e6f74; font-size: 14px; padding-bottom: 0; padding-left: 0; padding-right: 0; padding-top: 0;" valign="middle"><table border="0" cellpadding="0" <a href="http://cl.exct.net/?qs=bce38cfd33329019b3586d9543709eaf3e2e7782f06d48a901169a2bc1f42daeaab67258f1fe77e788419dc2a282f5e8" style="color: #5583c7;" target="_blank"><img alt="Nature's Sunshine" src="https://image.exct.net/lib/ff2c1c757166/i/4/096bf034-0.jpg" style="border-width: 0; display: block;" /></a>cellspacing="0" style="border-spacing: 0; color: #6e6f74; font-family: Arial, Helvetica, sans-serif; font-size: 14px;">
                                    <tbody>
<tr>

Here is what I have tried

"http://cl.exct.net/?qs=[a-z0-9]+$" or "http://cl.exct.net/\?qs=(.+?)"

Please get me where I can search and replace the string like at the top of the question.

Thanks,

Randal