pmpro-membership-profile-display.php

<?php
/*
 * Display Member Number on Edit Profile Page for Admin
 *
 */

// We have to put everything in a function called on init, so we are sure Register Helper is loaded.
function my_pmprorh_init_member_number() {
	// Don't break if Register Helper is not loaded.
	if ( ! function_exists( 'pmprorh_add_registration_field' ) ) {
		return false;
	}

	// Define the fields.
	$fields = array();
	$fields[] = new PMProRH_Field(
		'member_number',							// input name, will also be used as meta key
		'readonly',								// type of field
		array(
			'label'		=> 'Member Number',		// custom field label
			'size'		=> 40,				// input size
			'class'		=> 'member_number',		// custom class
			'profile'	=> 'only_admin',			// show in user profile	for admins		
		)
	);	

	// Add the fields into a new checkout_boxes are of the checkout page.
	foreach ( $fields as $field ) {
		pmprorh_add_registration_field(
			'checkout_boxes',				// location on checkout page
			$field							// PMProRH_Field object
		);
	}

	// That's it. See the PMPro Register Helper readme for more information and examples.
}
add_action( 'init', 'my_pmprorh_init_member_number' );