How to extract excel cells values/content in a .txt file?

To solve this problem you need to use macros in excel sheets.
You need to enable Developer toolbar in Excel 2007/2010 to use macros.
A simple VB script can handle this task.
In the VB toolbar just copy and run the below script and enjoy.

Sub a()
Open "<path>\file_output.txt" For Output As #1
Dim i As Integer
For i = 1 To 15
Print #1, Cells(i, 4)
Print #1, Cells(i, 5)
Print #1, "  "
Next i
Close #1
End Sub

In the above example script, 
a is the macro name. 
<path> needs to be specified where the required output file needs to be created.
In the for loop Cells(i, 4) and Cells(i, 5) specifies 4th column and 5th column of opened excel sheet. You can change according to your needs.
For further queries ask in the below comment section.