<script type="text/javascript">

    function getSelectionText(input) {
        var text = "";
        if (input.getSelection)
        {
            text = input.getSelection().toString();
        }
        else if (input.document.selection && input.document.selection.type != "Control")
        {
            text = input.document.selection.createRange().text;
        }
        return text;
    }

    var extInput = external.menuArguments;

    var selected = getSelectionText(extInput);

    var oShell = new ActiveXObject("Shell.Application");

    var commandtoRun = "MyFileLoc";

    oShell.ShellExecute(commandtoRun,"""+selected+""","","open","1");

</script>