Wie kann ich an eine Auslagerungdatei neue Einträge anfügen?

\RequirePackage{filecontents}
\newcounter{scratchnum}
\renewcommand \thescratchnum {\@roman\c@scratchnum}
\newcommand{\displayscratchnum}{\textsuperscript{\thescratchnum}}
\message{Message: Use latex --shell-escape filename}
\newcommand{\scratchname}{\Huge\hbox{\raise0.1ex\hbox{s}\raise0.1ex\hbox{c}\lower-0.2ex\hbox{r}%
\raise0.1ex\hbox{a}\lower0.065ex\hbox{t}\lower0.15ex\hbox{c}\lower0.3ex\hbox{h}}\hrule }
\newcommand{\scratchfile}{\def\scratchd{scratch.scr}
\IfFileExists{./\scratchd}{}
{\immediate\write18{echo \%NEUE SCRATCHDATEI aus \jobname.tex>\scratchd}}}
\newcommand{\scratch}[1]{\refstepcounter{scratchnum}%
\displayscratchnum\immediate\write18{echo
    \noexpand\\vskip0.5\noexpand\\baselineskip
    \jobname:\ \noexpand\\textsuperscript{\thescratchnum}
    \noexpand\\normalsize\ \unexpanded{#1}>>\scratchd}}
\newcommand{\scratches}{\subsection*{\scratchname}\relax 
\vskip0.5\baselineskip\parindent=0pt \input \scratchd
  \vskip2\baselineskip }
\newcommand{\clearscratch}{
\immediate\write18{echo \%NEUE SCRATCHDATEI aus
    \jobname.tex>\scratchd}}
\scratchfile
\begin{filecontents}{scratch.tex}
\documentclass[a4paper]{article}
\usepackage[ngerman]{babel}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage{scratch,multicol}
\begin{document}
\scratchfile
\begin{multicols}{2}
\scratches
\end{multicols}
\clearscratch
 \end{document} 
\end{filecontents}