package foo;
use Exporter;
use vars qw(@ISA @EXPORT);
@ISA=qw(Exporter);
@EXPORT=qw(myfunc);
sub myfunc {
  #something clever;
}

package main;
use foo; #imports myfunc, so that now
         # main::myfunc is an alias for
         # foo::myfunc

myfunc(1,2,3); #calls foo:myfunc(1,2,3)