Possible to launch dropdown from custom button?

[sterichards]

Ideally i'd like to hide the isteven button of:

<button id="" type="button" ng-click="toggleCheckboxes( $event ); refreshSelectedItems(); refreshButton(); prepareGrouping; prepareIndex();" ng-bind-html="varButtonLabel" ng-disabled="disable-button" class="ng-binding ng-click-active">Add/Remove Users<span class="caret"></span></button>

And replace it with a custom button that when pressed, launched the dropdown selection

The reason for this is that the content of the button is untidy for me and without being able to customise it with anything other than a selected objected property via button-label it makes it difficult to use this where I want it