在制表环境中自动排列间距

Question

\documentclass[10pt]{article}
\usepackage[paperwidth=5in,paperheight=8in, margin=1in, showframe]{geometry}


\newenvironment{myminipage}
{\par\addvspace{2ex}\nopagebreak\noindent\ignorespaces}
{\par\addvspace{2ex}\ignorespacesafterend}

\newenvironment{testenvironment}{%
\begin{minipage}[t]{3in}
\setlength{\topsep}{0pt}%
\setlength{\partopsep}{0pt}%
\begin{tabbing}
\hspace*{0.75in}\= \hspace*{0.75in}\= \hspace*{0.75in}\= \hspace*{0.75in} \kill
CL1 \> CL2 \> CL3 \> CL3\\
}%
{\end{tabbing}\end{minipage}}%


\begin{document}

\begin{myminipage}
some text\quad\hfill%
\begin{testenvironment}
\end{testenvironment}
\end{myminipage}

\end{document}

上面的定义中tabbing，列之间的间距是固定的。我该如何定义它，使它具有多少水平空间，并均匀划分列？