Custom section style and corresponding starred command

I need to use a custom format for a conference paper. I am asked to redefine the section, subsection and paragraph headings by the following code in the preamble:

\documentclass[a4paper,10pt,twocolumn]{article}\usepackage[utf8]{inputenc} % try latin1 if not working for you% styles of heading fonts, numbering etc\makeatletter\def\@normalsize{\@setsize\normalsize{10pt}\xpt\@xpt    \abovedisplayskip 10pt plus2pt minus5pt\belowdisplayskip    \abovedisplayskip \abovedisplayshortskip \z@    plus3pt\belowdisplayshortskip 6pt plus3pt    minus3pt\let\@listi\@listI}% section heading size and spacing\def\sect{\@setsize\sect{12pt}\xipt\@xipt}\def\section{\@startsection {section}{1}{\z@}{1.5ex}{0.2ex}{\large\bf} } % Original - remove point%\newcommand\mysection[1]{} % define header/footer%\newcommand\mysection{\@startsection{mysection}{1}{\z@}{1.5ex}{0.2ex}{\large\bf} }%\makeatother% subsection heading size and spacing\def\subsize{\@setsize\subsize{11pt}\xipt\@xipt}\def\subsection{\@startsection {subsection}{2}{\z@}{1.0ex}{0.2ex}{\subsize\bf} }\def\paragraph{\@startsection {paragraph}{4}{\z@}{0.6ex}{-1em}{\bf} }%\renewcommand{\abovecaptionskip}{0pt}%\renewcommand{\captionlabelfont}{\small \bf}%\renewcommand{\captionfont}{\small}\renewcommand{\figurename}{Fig.}%% make headings of sections have a trailing dot\renewcommand \thesection{\arabic{section}.}\renewcommand \thesubsection{\arabic{section}.\arabic{subsection}.}\renewcommand \thesubsubsection{\arabic{section}.\arabic{subsection}.\arabic{subsubsection}.}%\makeatother\begin{document}\section{Test}\label{sect:test}As shown in~\ref{sect:test}.\section*{Acknowledgment}Thank you.\end{document}

I am encountering the following problems:

1. I cannot use starred sections appropriately (Acknowledgements and Reference), I guess because no starred definition is provided. I am struggling in find a solution here.

Update1when I use \section*{Acknowledgements}, a heading containing "*" appears, and "Acknowledgements" appears below, in the body of the text. Same happens with "References".

2. The trailing dots are present also in the body of the manuscript, so if a section is referred at the end of a sentence, two dots appear (e.g., in Section 1.1..).

Update1is it possible to get rid of it without changing the heading style, to follow the conference template.

Could you help me how can improve the code (starred version of the section, avoid two consecutive doth in the body of the text)?Thanks in advance for your support.