主题：表达式？

Dim s As String = "<fea=""123"" />"
Dim i As Integer = s.IndexOf("""")
Dim j As Integer = s.LastIndexOf("""")
Output.Show(s.SubString(i + 1,j - i - 1))

或者：

Dim s As String = Tables("表A").Current("第一列")

Dim i As Integer = s.IndexOf("""")
Dim j As Integer = s.LastIndexOf("""")
Output.Show(s.SubString(i + 1,j - i - 1))

Dim fls As List(of String) = DataTables("表A").DataRows(0).Lines("第一列")   '把提取的内容复制到表A的第一行、第一列，测试。

提取内容的行数，按说是固定的，所以：
For i As Integer = 13 To 15
    Dim j As Integer = fls(i).IndexOf("""")
    Dim k As Integer = fls(i).LastIndexOf("""")
    Output.Show(fls(i).SubString(j + 1,k - j - 1).Trim("省"))
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