用正则表达是从下段文字中获取一些信息？

[xiamin]

------=_Part_160851_521012112.1320051571633
Content-Type: text/plain; charset=gbk
Content-Transfer-Encoding: base64

N3W/2tPvaWk8YnI+PGJyPkF0IDIwMTEtMTAtMzEg
MTY6NTk6MDMsamF2YW1haWwyMDAwQDE2My5j
b20gd3JvdGU6PGJyPiA8YmxvY2txdW90ZSBp
ZD0iaXNSZXBseUNvbnRlbnQiIHN0eWxlPSJQQURE
------=_Part_160851_521012112.1320051571633--
获取如下信息：
获取编码信息gbk
获取Transfer-Encoding编码信息

[bzcode]

我在C++下做过邮件格式的恢复，不过没有使用正则表达式。

等高手来回答。

[人生难得一只鸡]

 StreamReader sr = new StreamReader(@"C:\Documents and Settings\Administrator\桌面\Test.txt", Encoding.GetEncoding("GB2312"));
            string tempStr =sr.ReadToEnd();
            string pattern = @"[\s\S]*charset=([\s\S]*)Content-Transfer-Encoding:\s*([^\s]+)[\s\S]*";
            string gbk = Regex.Replace(tempStr,pattern,"$1");//gbk
            string encoding = Regex.Replace(tempStr, pattern, "$2");//base64