[Alan @ CIT]

The easiest way is just to find a dropdown in the regular vBulletin options, click on "Edit" link next to it and copy the code

For example, the "Enable Forum Leaders" dropdown option in vB->Options has an option code of:

<select name=\"setting[$setting[varname]]\" tabindex=\"1\" class=\"bginput\">
<option value=\"0\" " . iif($setting['value']==0,'selected="selected"') . ">$vbphrase[no]</option>
<option value=\"1\" " . iif($setting['value']==1,'selected="selected"') . ">$vbphrase[yes]</option>
<option value=\"2\" " . iif($setting['value']==2,'selected="selected"') . ">$vbphrase[yes_but_disable_moderators]</option>
</select>

So essentially, you just have to write the <select> code yourself.

Thanks,
Alan.