ceo.sty をインストールできていることが前提ですが
こんなことをすれば，英数字はceoのものになります。

\documentclass{jarticle}

\usepackage{emath}
\usepackage{hako}

\renewcommand{\rmdefault}{ceo}
\DeclareSymbolFont{operators}{OT1}{ceo}{m}{n}
\SetSymbolFont{operators}{bold}{OT1}{ceo}{bx}{n}
\def\operator@font{\mathgroup\symoperators}
\DeclareSymbolFontAlphabet{\mathrm}{operators}
\DeclareMathAlphabet{\mathbf}{OT1}{ceo}{bx}{n}
\DeclareMathAlphabet{\mathit}{OT1}{ceo}{m}{it}
\SetMathAlphabet{\mathit}{bold}{OT1}{ceo}{bx}{it}
\DeclareSymbolFont{letters}{OML}{ceo}{m}{it}
\SetSymbolFont{letters}{bold}{OML}{ceo}{bx}{it}
\DeclareFontSubstitution{OML}{ceo}{m}{it}

\begin{document}

\begin{enumerate}[(1)]
\item $a+b\times c\div d- e^f_gh ijkl$ $mnop qrst uvwx yz 1234567890$
\item abcd efgh ijkl mnop qrst uvwx yz ffl ffi 1234567890
\item あかさたなはま(やらわ)ん
\item
The reason for such different levels of complexity is that people change
as they grow accustomed to any powerful tool. When you first try to use \TeX,
you'll find that some parts of it are very easy, while other things will take
some getting used to.

\item $\int_0^4 x^3\sqrt{x} dx$
\item $\displaystyle\int_0^4 x^3 dx$
\item $\sqrt{\frac12}$ $\sqrt{\dfrac12}$ $\sqrt{\bunsuu12}$
\end{enumerate}

\hakosyokika
$\frac{\Hako+\Hako+\Hako}{2}$

$\dfrac{\Hako+\Hako+\Hako}{2}$

$\bunsuu{\Hako+\Hako+\Hako}{2}$

\end{document}

▼関連発言
│
└◆6482:ceoとの連携の提案 [tommy_minor] 09/24 20:53
　└◆6496:Re:ceoとの連携の提案 [石原　守] 09/25 20:23
　　└◆6497:Re[2]:ceoとの連携の提案 [tommy_minor] 09/26 03:01
　　　├◆6504:--- [---] 09/27 10:39
　　　└◆6505:Re[3]:ceoの英数字のみをemathと使う [石原　守] 09/27 11:54<-last