\newcommand{\theheading}{}
\newcommand{\heading}[1]{\gdef\theheading{#1}}

\newcommand{\theleftbox}{}
\newcommand{\leftbox}[1]{\gdef\theleftbox{#1}}

\newcommand{\therightbox}{}
\newcommand{\rightbox}[1]{\gdef\therightbox{#1}}

\newcommand{\makecustomtitle}{%
    \begin{titlepage}%
        \vspace{1cm}%
        \begin{center}%
            \hrule\vspace{0.4cm}%
            {\Large\textbf{\theheading}\par}%
            {\linespread{0.8}\Large\makeatletter\@title\makeatother\par}%
            \vspace{0.2cm}%
            {\makeatletter\@author\makeatother}%
            \vspace{0.6cm}\hrule%
        \end{center}%
        \vfill{}%
        \begin{minipage}[t]{0.5\textwidth}%
        \begin{flushleft}%
            \theleftbox%
        \end{flushleft}%
        \end{minipage}%
        \begin{minipage}[t]{0.5\textwidth}%
        \begin{flushright}%
            \therightbox%
        \end{flushright}%
        \end{minipage}%
    \end{titlepage}\ignorespaces\makeatletter\gdef\@title\empty\gdef\@author\empty\makeatother}