macro recursion

\documentclass{article}

\makeatletter
\newcommand\myrepeat[3]{%
    % #1 is the number of repetitions
    % #2 is the code to repeat
    % #3 is the code to put in the middle
    \expandafter\myrepeat@aux\expandafter{\romannumeral\number\number#1 000}{#2}{#3}%
}
\newcommand{\myrepeat@aux}[3]{\myrepeat@auxi{#2}{#3}#1;;}
\def\myrepeat@auxi#1#2#3#4{%
    \ifx#3;%
    \expandafter\@gobble % recursion has ended
    \else
    \expandafter\@firstofone % still one m to swallow
    \fi
    {\myrepeat@auxii{#1}{#2}{#4}}%
}
\def\myrepeat@auxii#1#2#3{%
    #1\ifx#3;\else#2\fi
    \myrepeat@auxi{#1}{#2}#3% restart the recursion
}
\makeatletter

\begin{document}

    \myrepeat{5}{Non devo}{\\}

\end{document}