Hi Ewa,

I just tried Arck Tang's suggestion and it works perfectly - but the Month column must be formatted as Text in order for this trick to work.

To format the column (in this case Column A) as text, click on the letter A at the top of the column and press Command-1. In the dialog, look for Text in the list of formatting options and then click the OK button.

If you plan to use the months as dates in calculations or for automatic displays such as conditional formatting, pivottables, slicers, etc where you want Excel to know the date value, you'll need to add an additional column foratted as Date. You can always hide the extra column, but you may need to use the date values instead of text for certain features.

You can't natively use super/sub scripts in Excel Chart labels. However, you can use a fairly simple trick to get Excel to do it.

1. Create your chart with your data.
2. Add three helper columns to use for your axis label points. Use your preferred x-values and use 0 for your y-values, then add a column for your preferred label (e.g. 2^14, as 214).
3. Add the points from your helper columns to your chart.
4. Format the new series (which should be a series of points along the x-axis) to no point (or a cross, if you'd prefer a "tick" on the axis).
5. Now, you'll need to download Rob Bovey's XY Chart Labeler and install it as an Excel add-in. If you want to break out of Excel's basic formatting to do interesting Charts, this is a must-have (or you could write your own version in VBA).
6. Using Chart Labeler, select your helper series and assign the label column as your series' labels, with a location = Bottom.
7. Finally, select the superscript portion of each label and format your font for superscript. This has to be done individually for each label. Also, if you update the values, you'll have to reformat.

I have 2 ways:

1. If you are using only the "1", "2" and "3" digits in superscript, you can change them to these characters:

• character ¹: in your keyboard: alt+0185 / US-International Keyboard: altgr+1
• character ²: in your keyboard: alt+0178 / US-International Keyboard: altgr+2

• character ³: in your keyboard: alt+0179 / US-International Keyboard: altgr+3
  
  

  1.1. Note: In alt+#### and similar combos, you have to hold alt and then hit the digits from numpad number keys (not the ones above letters), i.e., alt+0185 = hold alt, press numpad 0, press numpad 1, press numpad 8, press numpad 5, release alt

  1.2. Note: I'm not sure about the name of "US-International Keyboard", but in a lot of keyboards I used (one had a similar name) that combos (altgr+1, 2 or 3) worked.

2. You can use another character font. Some fonts are designed for math, so:

2.1. Install one of these fonts:

• DejaVu (and its variants - Sans: normal, condensed, light, mono / Serif: normal, condensed): I think it is the more known of my list
• Cambria Math
• Candara
• Consolas
• Constantia
• Corbel
• Lucida Sans Unicode
• Segoe UI
  
  

2.2. Open your excel file, select cells containing legend text and change font to one of these

2.3. Use Windows Charmap (Start > Run > Charmap) or Office Insert > Symbol menu to copy and paste or insert superscript (or subscript) characters you want on the contentes of these cells

2.4. Double click on graph, select the legend and change font to the chosen one

2.5. See an example in my Google Docs using DejaVu Sans: https://docs.google.com/leaf?id=0B0HwU0hzcrxVNjA2NTRkOTAtNjc1My00ZDVmLWJjZGUtODIzZDlhMDk4ZDRl&hl=pt_BR

HOT TRICK!!!!!!!

If can only copy-paste following characters (including letters) in superscript and subscript. Do it in your Excel file. Remember to use Unicode fonts (you can use mentioned fonts above / this text was copied from Wikipedia and Chris Morgan's answer on a StackOverflow question and edited):

Consolidated for cut-and-pasting purposes, the Unicode standard defines complete sub- and super-scripts for:

• numbers and common mathematical symbols ( ⁰ ¹ ² ³ ⁴ ⁵ ⁶ ⁷ ⁸ ⁹ ⁺ ⁻ ⁼ ⁽ ⁾ ₀ ₁ ₂ ₃ ₄ ₅ ₆ ₇ ₈ ₉ ₊ ₋ ₌ ₍ ₎ )

• a full superscript Latin lowercase alphabet except q ( ᵃ ᵇ ᶜ ᵈ ᵉ ᶠ ᵍ ʰ ⁱ ʲ ᵏ ˡ ᵐ ⁿ ᵒ ᵖ ʳ ˢ ᵗ ᵘ ᵛ ʷ ˣ ʸ ᶻ )

• a limited uppercase Latin alphabet ( ᴬ ᴮ ᴰ ᴱ ᴳ ᴴ ᴵ ᴶ ᴷ ᴸ ᴹ ᴺ ᴼ ᴾ ᴿ ᵀ ᵁ ⱽ ᵂ ) - no C, F, Q, S, X, Y, Z

• a few subscripted lowercase letters ( ₐ ₑ ₕ ᵢ ₖ ₗ ₘ ₙ ₒ ₚ ᵣ ₛ ₜ ᵤ ᵥ ₓ )

• and some Greek letters ( ᵅ ᵝ ᵞ ᵟ ᵋ ᶿ ᶥ ᶲ ᵠ ᵡ ᵦ ᵧ ᵨ ᵩ ᵪ ).

Note that since these glyphs come from different ranges, they may not be of the same size and position, depending on the typeface.

Figured it out. "Right clicking" on the highlighted number and selecting "Font..." from the drop-down menu instead of hitting the Command+T shortcut opens up a different-looking text editing window and ticking the subscript box there successfully changes the text. Hope this also helps someone else.