怎么使用C#正则替换一段字符串

如何使用C#正则替换一段字符串
源字符串为：
<img class="SIGN" title="签章控件:sfsdfsdfsdf" border="0" name="DATA_10" alt="" align="absMiddle" value="sfsdfsdfsdf" 

sign_type="1,1," style="cursor: hand" src="/module/html_editor/editor/images/sign.gif" />&#160

以class="SIGN"为特征标记，遇到class="SIGN"的img标签就替换

最终将上面的源字符串替换为
<div class='websign' id=SIGN_POS_DATA_10 sign_type="1,1,">&nbsp;<input type=button value=盖章 

onclick="addSeal('DATA_10')">
<input type=button value=手写 onclick="handWrite('DATA_10')">
<input type=hidden name=DATA_10 value=''>
</div>

[解决办法]

C# code

(?is)<img.*?class="sign"[^>]*>
[解决办法]
<img\s*class="SIGN".*?name="([^"]*)"[^>]*>
[解决办法]
C# code
            string input = @"<img class=""SIGN"" title=""签章控件:sfsdfsdfsdf"" border=""0"" name=""DATA_10"" alt="""" align=""absMiddle"" value=""sfsdfsdfsdf""  sign_type=""1,1,"" style=""cursor: hand"" src=""/module/html_editor/editor/images/sign.gif"" />";            Console.WriteLine(new Regex(@"(?is)<img.*?class=""sign""[^>]*>").Replace(input, @"<div class='websign' id=SIGN_POS_DATA_10 sign_type=""1,1,"">&nbsp;<input type=button value=盖章  onclick=""addSeal('DATA_10')""><input type=button value=手写 onclick=""handWrite('DATA_10')""><input type=hidden name=DATA_10 value=''></div>"));
[解决办法]
探讨


原来是
<img class="SIGN" title="签章控件:sfsdfsdfsdf" border="0" name="DATA_10" alt="" align="absMiddle" value="sfsdfsdfsdf" sign_type="1,1," style="cursor: hand" src="/module/html_editor/editor/images/sig……

[解决办法]
我也想知道答案
[解决办法]
稍微有点理解了，lz你说清那些数据是关联对应的啊！