
% command, prefix, arguments
\def\makefontcommander#1#2{%
\def\makefontcommands##1{\ifx##1\endmakefontcommands%
\else\expandafter\def\csname#2##1\endcsname{#1{##1}}%
\expandafter\makefontcommands%
\fi}%
\def\makecsfontcommands##1{\ifx##1\endmakecsfontcommands%
\else\expandafter\def\csname#2##1\endcsname{#1{\csname##1\endcsname}}%
\expandafter\makecsfontcommands%
\fi}%
}

% example use:  
% \makefontcommander{\overline}{o}
% \makefontcommands{ABCDEF}
%
% will create \oA = \overline{A}, ..., \oF = \overline{F}
