How to rename headers for the cross-reference list

Hello,

I have numbered chapters, formatted as headers, and these headers are
provided automatically in the cross-reference list. I use this feature
for a self-brewn index. But also the PDF-Viewer seems to recon these
entries and provides them as document index automatically. That's ok
with me, even though I'd like to have more control over this, but the
names were autogenerated by LibreOffice (just taking the header content
an dropping spaces and tabs) and read awkward. I want to change them, as
also not all of the header should be in the reference name. How can I
change these entry names in the cross-reference list?

Regards,

Do not wonder! This is the corrected text to the incorrect mail with
wrong subject...

Hello,

I have numbered chapters, treated as headings, and these headings
are provided automatically in the cross-reference list. I use this
feature for a self-brewn index. But also the PDF-Viewer seems to
recon these entries and provides them as document index
automatically. That's ok with me, even though I'd like to have more
control over this, but the names were autogenerated by LibreOffice
(just taking the content of the heading an dropping spaces and tabs)
and read awkward. I want to change them, as also not all of the
heading should be in the reference name. How can I change these entry
names in the cross-reference list?

Regards,