Formatting a second index

[Lebber]

I managed to insert a second index into a Word 2010 document that already had one by manually adding

/f "mon"

to all entries that are only meant for the second "mon" index. However, I can't format that second index. Whenever I try to do so, the text in the field is ALWAYS overwritten and Word simply insert the first index a second time.
I already wasted a couple of hours on this; can anybody help?

[Stefan Blom]

Which formatting are you trying to change? Please elaborate.

[eNGiNe]

Sounds to me – reading "generate" instead of "format" – as though OP is trying to set up and maintain two separate indexes, though I've not checked the switch he mentions. Lebber, have I understood your problem correctly?

[Lebber]

Indeed I added a second index. Whenever I selected it and tried to format it via context menu, it turn into a copy of the first index (index, not table of contents).

However, I could finally solve that by manually using field commands (there is a list of field commands on Microsoft's website).