C/C++编程：txt文件中提取数据
txt文件中内容的格式为：
“5”，“23:45:34:78:21:45”,"-34","sdfsdfdsf"
“7”，“32:47:34:89:21:75”,"-80","sdfsdfsdf"
“5”，“23:45:34:78:21:45”,"-54","sdfsdfdsf"
“7”，“32:47:34:89:21:75”,"-27","sdfsdfsdf"
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每一行格式都是一模一样的。我想提取出-34、-80、-54、-27那一列的数据，请问各位高手用C/C++该如何处理，怎么实现？？？
