<a href="http://abc123.linkbucks.com"><img src="http://img187.imagevenue.com/loc1115/th_99189_image_122_1115lo.jpg" /></a>

<a href="http://img187.imagevenue.com/loc1115/th_99189_image_122_1115lo.jpg"><img src="http://img187.imagevenue.com/loc1115/th_99189_image_122_1115lo.jpg" /></a>

<a href="http://img187.imagevenue.com/img.php?image=99189_image_122_1115lo.jpg"><img src="http://img187.imagevenue.com/loc1115/th_99189_image_122_1115lo.jpg" /></a>

# 1st step:
search expression: (<a href=")[^"]*("><img src=")([^"]*)"
replacement:       1323"

# 2nd step:
search expression: (<a href="[^"]*)/loc[^/]*/th_
replacement:       1/img.php?image=