Suppose I have a word file with content as follows:

\sed{a}\sed{b}\sed{sfwere}\sed{sfwerwerwefd}\sed{s fwerwe}\sed{werwe}
\vlm{n}\vlm{p}\vlm{w}\vlm{serw}\vlm{swer}
\beex \bea f(t)=g(t)\eea\eeex

\beex \bea wrwerwerwerwe\eea\eeex

I need to repalce them as follows:

\sed{a} is replaces to \left\{a\right\}
\sed{b} is replaces to \left\{b\right\}
\sed{sfwere} is replaces to \left\{sfwere\right\}

etc.

\vlm{n} is replaces to \lim_{n\to\infty}
\vlm{p} is replaces to \lim_{p\to\infty}
\vlm{w} is replaces to \lim_{w\to\infty}

etc.

\beex \bea f(t)=g(t)\eea\eeex

is replaces to

\begin{equation}\begin{array} f(t)=g(t)\end{array}\end{equation}


How can I realize it?