Subscript and superscript in automatic index

I created a writer file in which there are paragraphs titles with subscript and superscript text. When I create the index automatically the subscript and superscript parameters are lost. If I try to select the text in the index I can not select to make the text nor subscript neither superscript.

I have Ubuntu 12.04 with libreoffice 3.5.4.2.

Bug 30732 - Character formatting not retained in entries of TOC, table lists, etc. [2010-10-09]

OOo Bug 27377 - Character formatting not retained in entries of TOC, table lists, etc. [2004-04-02]

You can edit the text (for the final version [1]) via

right-click on index (context menu) → Edit Index/Table… → Index/Table tab →

☐ Protected against manual changes (disabled) → OK.

[1] An upgrade of the index/table will remove your manual changes.

I believe that you did not answer the basic question which is one that I have: is there a way to keep certain formatting in the index? It is tempting to say that only superscript/subscript ought to be retained, but I’m sure that other authors would want to keep other formatting. To me subscript/superscript is the most important formatting to be retained, because without it, crucial information is lost like sulfate anion (SO4-2) is supposed to be

SO4-2