Passing variable to email template (Perch Shop)

Hi there,

I'm trying to pass a value of id="telephone" so it's rendered at order_dispatched.html email template ( + Apps>Orders ). Is there a quick way to do that?

User account creation at the checkout:

<div class="form-group">
            <perch:label for="first_name" class="">First name</perch:label>
            <perch:input type="text" class="form-control input-lg" id="first_name" required="true" label="First name" />
            <perch:error for="first_name" type="required">Please add your name</perch:error>
        </div>

        <div class="form-group">
            <perch:label for="last_name" class="">Last name</perch:label>
            <perch:input type="text" class="form-control input-lg" id="last_name" required="true" label="Last name" />
            <perch:error for="last_name" type="required">Please add your name</perch:error>
        </div>

        <div class="form-group">
            <perch:label for="telephone" class="">Telephone</perch:label>
            <perch:input type="text" class="form-control input-lg" id="telephone" required="true" label="Telephone" />
            <perch:error for="telephone" type="required">Please add your telephone number</perch:error>
        </div>

        <div class="form-group">
            <perch:label for="email">Email</perch:label>
            <perch:input type="email" class="form-control input-lg" id="email" required="true" placeholder="you@company.com" helper="PerchMembers_Members::check_email" />
            <perch:error for="email" type="required">Please add your email address</perch:error>
            <perch:error for="email" type="helper">That email address is already in use</perch:error>
            <perch:input type="hidden" id="password" value="__auto__" />
        </div>