my %coderefs = (
    foo => \&Module::function_foo,
);
my $function = 'foo';
my $coderef = $coderefs{$function};
unless ($coderef){
  # do something about the missing function
  # (for example try to load it from the module
  # and augment the %coderefs, this would eliminate
  # the need to manually set up %coderefs in advance)
}
my $result = $coderef->('some parameters');