How can I **automatically** create an Index of a pdf generated as below?

Question

I have posted a similar question elsewhere

but the answer there has a serious drawback, it must be manually inserted the section names, while my dream was that it should be fully automatically generated from the R0.pdf files which are present in the same CWD. And everything should be in XeLaTeX

Here I just restate my original question:

I have a pdf generated as below. Now I would like to create the index which should be a page listing all the names of papers included, i.e. the names of sections, one row should be dedicated for each paper from the entire pdf. How could I achieve this ? Preferably in XeTeX.

\documentclass[landscape,a4paper]{article}
\usepackage{pdfpages}
\usepackage{pgfmath}
%\usepackage[margin=1cm,showframe]{geometry}% MWE only
\pgfmathsetmacro{\scale}{(\paperheight-2cm)/(\paperwidth-3cm)}% 1cm margin
\pgfmathsetlengthmacro{\delta}{\paperwidth-2cm-2\scale(\paperheight-3cm)-4mm}% 4mm fudge factor
\usepackage[footwidth=paper]{scrlayer-scrpage}
\pagestyle{plain}
\usepackage{polyglossia}
\usepackage{fontspec}
\setotherlanguage{hebrew}
\newfontfamily\hebrewfont{Arial}
\robustify{\thepage}
\renewcommand{\thepage}{\arabic{page} \ \roman{page}\ \texthebrew{\hebrewnumeral{\value{page}}}}
\newcommand\gettitle[1]{%
  \directlua{%
    local filename = kpse.find_file("#1", 'graphic/figure')
    doc = pdfe.open(filename)
    info = pdfe.getinfo(doc)
    title = info['Title']
    tex.print(title)
  }}
\begin{document}
%  \includepdf[scale=1.02, nup=2x1,pages=1-8,trim=2.5cm 2.5cm 5.5cm 7.0cmB]{sh1.pdf}
%pagecommand={\thispagestyle{plain}}
\includepdf[scale=\scale,noautoscale,nup=2x1,pages=1-,delta={\delta} 0pt,offset=0pt -3mm,% offset in reverse order
  trim=2.5cm 2.5cm 5.5cm 7.0cm,picturecommand={\put(.15\paperwidth,3.3cm){\thepage}}]{example-image-a4-numbered.pdf}
\includepdf[scale=\scale,noautoscale,nup=2x1,pages=1-,delta={\delta} 0pt,offset=0pt -3mm,% offset in reverse order
  trim=2.5cm 2.5cm 5.5cm 7.0cm,picturecommand={\put(.15\paperwidth,3.3cm){\thepage}}]{example-image-a4-numbered.pdf}
\includepdf[scale=\scale,noautoscale,nup=2x1,pages=1-,delta={\delta} 0pt,offset=0pt -3mm,% offset in reverse order
  trim=2.5cm 2.5cm 5.5cm 7.0cm,picturecommand={\put(.15\paperwidth,3.3cm){\thepage}}]{example-image-a4-numbered.pdf}
\end{document}