Indesing Notas al Pie

Create your Paragraph and Character styles for Footnotes

Go to Type>Document Footnote Options

Set your Footnote Paragraph formating to your Paragraph Style for Footnotes

In the Character Styles - edit your footnote number

Change your formatting to Superscript (and any other setting you want - like Italic or whatever way you wish it to look like)

In the paragraph style - edit Footnotes

Insert this code and in the Apply Style - set it to the Footnote Number

^.+(?=\t)

This grep code works for any text at the begining of a paragraph up to a Tab

So it might not work for your specific setting - if you show us a sample document we can help further if this is not working

Now when you insert a footnote it will automatically go to superscript in the numbering

You can further enhance your look with the Character Style

For example

I've applied a greater baseline shift 

and applied an underline for an effect

Attached is an InDesign file that shows the settings I have described

Let us know if you need any further assistance.

Thanks