How to Create a textbox with an equal spacing between words using C#?

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C#

VSTO

PowerPoint

VS2013

Hi,
I am using VS2013 C#.net for creating my PowerPoint Add-in. In which I am in a situation to create a textbox(only one textbox) that contains titles of each slide and slide number.

Note: I am looping over slides and storing the results in a same string variable.

For example,
the resulting textbox will contain,
Introduction     1
Abstract           2
Code                3
Conclusion       4 ....
And it continues.

But my problem is I should use only textbox and not a table to have the same spacing between text and number.
And I am not able to get the above (table like)spacing.
Can any one please help me get it?
Thanks in Advance!!!