Is there a Hook / Filter to manipulate form output?

Hey,

While styling my contact form page, I need to add a container element around the select (dropdown), or modify the <div class="ginput_container"> code where the element contained within is a dropdown.

Is there a hook or filter that would help me to do this, specifically only for dropdown elements?

i.e. The current output looks like:

<li class="gfield gfield_contains_required" id="field_1_4">
    <label for="input_1_4" class="gfield_label">Drop Down<span class="gfield_required">*</span></label>
    <div class="ginput_container">
        <select tabindex="13" class="medium gfield_select" id="input_1_4" name="input_4">
            <option value="First Choice">First Choice</option>
            <option value="Second Choice">Second Choice</option>
            <option value="Third Choice">Third Choice</option>
        </select>
    </div>
</li>

I need it to look like this:

<li class="gfield gfield_contains_required" id="field_1_4">
    <label for="input_1_4" class="gfield_label">Drop Down<span class="gfield_required">*</span></label>
    <div class="ginput_container select-wrapper">
        <select tabindex="13" class="medium gfield_select" id="input_1_4" name="input_4">
            <option value="First Choice">First Choice</option>
            <option value="Second Choice">Second Choice</option>
            <option value="Third Choice">Third Choice</option>
        </select>
    </div>
</li>

or this:

<li class="gfield gfield_contains_required" id="field_1_4">
    <label for="input_1_4" class="gfield_label">Drop Down<span class="gfield_required">*</span></label>
    <div class="ginput_container">
     <div class="select-wrapper">
        <select tabindex="13" class="medium gfield_select" id="input_1_4" name="input_4">
            <option value="First Choice">First Choice</option>
            <option value="Second Choice">Second Choice</option>
            <option value="Third Choice">Third Choice</option>
        </select>
    </div>
    </div>
</li>

I know this can probably be done with jQuery if not by modifying the output with a hook / filter, but I don't know how to do this.

Any help is greatly appreciated!

James