求帮，修改一个正则 preg_replace 替换问题

Question

正则

Answer 1

$con = <<<context
     山萸肉：货源走动不及产新初期，价疲，统货31-32元，优质选货45元。<br />
     山桃仁：货源走动不急年前，价格小幅下滑，现市场山桃仁净货60-65元。 <br />
     补骨脂：新货来市增多，价滑，统货7-7.5元，随着新货继续上市，后市有下滑空间。<br />
     蛇床子：货源走动顺畅，价格坚挺，统货20元上下，净货22元，该品库存小，关注商家多。 <br />
     猫爪草：货源走动不佳，家种货价滑明显，统货92元左右，野生品依然价坚，统货170-180元。<br />
     生地：货源走动顺畅，价格开始转稳，市场混统货13-13.5元，三级货15-16元。 <br />
     黄连：货源走动正常，价稳，统货92-93元，随着货源消化，后市仍有走高可能。<br />
     板蓝根：近期大货走动一般，价稳，东北统货8.5-8.8元，甘肃货9-9.5元。 <br />
     巴戟天：货源走动顺畅，价坚，现市场巴戟肉统货45元，好的选货53元上下。<br />
     郁金：货源走动不佳，价疲，九成干新统货18-19元，统片20-22元。 <br />
     姜黄：货源走动顺畅，但价格暂稳，现市场统个5.5-6元，姜黄片7-7.5元。 <br />
     桔梗：年后货源走动较好，价坚，地产统货23元上下，关注商不多。<br />
     赤芍：资源少，来货不多，走动仍好，现内蒙京赤芍48-52元，统片55-58元。 <br />
     菊饼：货源走动正常，价坚，亳州地产菊花饼40-42元，杭菊花饼50-55元。 <br />
     香附：货源走动正常，价稳，市场毛附9.5元上下，统片在13.5元左右。<br />
<br />
<img alt="" width="500" height="375" src="http://www.zzyycc.com/file/upload/201402/28/20-14-07-69-1.jpg" /> 
 
context;
$con = preg_replace('/(?=[^>]*(?=<(?!>)|$))\d/', '<img src="image/$0.gif">', $con);
echo $con;
&nbsp;&nbsp;&nbsp;&nbsp; 山萸肉：货源走动不及产新初期，价疲，统货<img src="image/3.gif"><img src="image/1.gif">-<img src="image/3.gif"><img src="image/2.gif">元，优质选货<img src="image/4.gif"><img src="image/5.gif">元。<br />
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;山桃仁：货源走动不急年前，价格小幅下滑，现市场山桃仁净货<img src="image/6.gif"><img src="image/0.gif">-<img src="image/6.gif"><img src="image/5.gif">元。&nbsp;<br />
&nbsp;&nbsp;&nbsp;&nbsp; 补骨脂：新货来市增多，价滑，统货<img src="image/7.gif">-<img src="image/7.gif">.<img src="image/5.gif">元，随着新货继续上市，后市有下滑空间。<br />
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;蛇床子：货源走动顺畅，价格坚挺，统货<img src="image/2.gif"><img src="image/0.gif">元上下，净货<img src="image/2.gif"><img src="image/2.gif">元，该品库存小，关注商家多。&nbsp;<br />
&nbsp;&nbsp;&nbsp;&nbsp; 猫爪草：货源走动不佳，家种货价滑明显，统货<img src="image/9.gif"><img src="image/2.gif">元左右，野生品依然价坚，统货<img src="image/1.gif"><img src="image/7.gif"><img src="image/0.gif">-<img src="image/1.gif"><img src="image/8.gif"><img src="image/0.gif">元。<br />
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;生地：货源走动顺畅，价格开始转稳，市场混统货<img src="image/1.gif"><img src="image/3.gif">-<img src="image/1.gif"><img src="image/3.gif">.<img src="image/5.gif">元，三级货<img src="image/1.gif"><img src="image/5.gif">-<img src="image/1.gif"><img src="image/6.gif">元。&nbsp;<br />
&nbsp;&nbsp;&nbsp;&nbsp; 黄连：货源走动正常，价稳，统货<img src="image/9.gif"><img src="image/2.gif">-<img src="image/9.gif"><img src="image/3.gif">元，随着货源消化，后市仍有走高可能。<br />
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;板蓝根：近期大货走动一般，价稳，东北统货<img src="image/8.gif">.<img src="image/5.gif">-<img src="image/8.gif">.<img src="image/8.gif">元，甘肃货<img src="image/9.gif">-<img src="image/9.gif">.<img src="image/5.gif">元。&nbsp;<br />
&nbsp;&nbsp;&nbsp;&nbsp; 巴戟天：货源走动顺畅，价坚，现市场巴戟肉统货<img src="image/4.gif"><img src="image/5.gif">元，好的选货<img src="image/5.gif"><img src="image/3.gif">元上下。<br />
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;郁金：货源走动不佳，价疲，九成干新统货<img src="image/1.gif"><img src="image/8.gif">-<img src="image/1.gif"><img src="image/9.gif">元，统片<img src="image/2.gif"><img src="image/0.gif">-<img src="image/2.gif"><img src="image/2.gif">元。&nbsp;<br />
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;姜黄：货源走动顺畅，但价格暂稳，现市场统个<img src="image/5.gif">.<img src="image/5.gif">-<img src="image/6.gif">元，姜黄片<img src="image/7.gif">-<img src="image/7.gif">.<img src="image/5.gif">元。&nbsp;<br />
&nbsp;&nbsp;&nbsp;&nbsp; 桔梗：年后货源走动较好，价坚，地产统货<img src="image/2.gif"><img src="image/3.gif">元上下，关注商不多。<br />
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;赤芍：资源少，来货不多，走动仍好，现内蒙京赤芍<img src="image/4.gif"><img src="image/8.gif">-<img src="image/5.gif"><img src="image/2.gif">元，统片<img src="image/5.gif"><img src="image/5.gif">-<img src="image/5.gif"><img src="image/8.gif">元。&nbsp;<br />
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;菊饼：货源走动正常，价坚，亳州地产菊花饼<img src="image/4.gif"><img src="image/0.gif">-<img src="image/4.gif"><img src="image/2.gif">元，杭菊花饼<img src="image/5.gif"><img src="image/0.gif">-<img src="image/5.gif"><img src="image/5.gif">元。&nbsp;<br />
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;香附：货源走动正常，价稳，市场毛附<img src="image/9.gif">.<img src="image/5.gif">元上下，统片在<img src="image/1.gif"><img src="image/3.gif">.<img src="image/5.gif">元左右。<br />
<br />
<img alt="" width="500" height="375" src="http://www.zzyycc.com/file/upload/201402/28/20-14-07-69-1.jpg" />