New fields on submission

Hi, I would like to add a new select with options on this file:
/lib/pkp/templates/submission/submissionMetadataFormFields.tpl

{if $languagesEnabled || $subjectsEnabled || $keywordsEnabled || $agenciesEnabled || ($citationsEnabled && !$metadataModal) || $disciplinesEnabled}
	{fbvFormArea id="tagitFields" title="submission.submit.metadataForm"}
		{if $languagesEnabled}
                    {php}
                    
                    $this->assign("myarray", array( 
								op1=> "Option1", 
								op2 => "Options2", 
								op3 => "Option3", 
							));
                    $this->assign("mySelection", $newOptions);
                    {/php}
                <select name="Options" title="New Options">
                    {html_options  output=$myarray values=$myarray selected=$newOptions }
                </select>                    

How can I save this options on my database?
I created a new get and setters in /lib/pkp/classes/submission/Submission.inc.php but it’s not working.

When I am on submission and edit it, I would like this select on my Metadata menu.

Any help ??
Regads,
xavi