First off, DynaLoader is not mandatory for what you want to do. Someone will probably explain you its use, because I personally don't know much about it. I know however that Exporter should be enough.

Second, you have a syntax error that would have been reported, had you turned on warnings.

@ISA = qw(Exporter, DynaLoader);

should be

Last, it's not necessary to specify which subroutine to import when using @EXPORT. It's only mandatory when going with @EXPORT_OK

Putting it all together, something like that will do what you want:

package MyModule;

use strict;
use warnings; # might want to turn this off once everything works fine
use Exporter;

our (@ISA, @EXPORT);
@ISA = qw(Exporter);
@EXPORT = qw(suba);

sub suba {
        print "suba\n";
}

1;
[download]

Then, in your code:

#!/usr/bin/perl
use strict;
use warnings;
use MyModule;

suba();
[download]

Update: I had forgotten the necessary use Exporter; line... shame on me. Anyway, you'll want to read perldoc Exporter.