I had the same issue, i solved it with WPallImport (http://www.wpallimport.com/).
It has support for hooks and functions so after importing / saving any post, just reference to some function in order to save the location data for GeoMyWP.
Make sure you have the custom fields imported, otherwise this will not work.
(not all custom fields are required)
_wppl_street
_wppl_apt
_wppl_city
_wppl_zipcode
_wppl_state
_wppl_country
_wppl_phone
_wppl_fax
_wppl_email
_wppl_website
Put the stuff below in your theme function file:
(just to be complete, I have the gravity forms addon and I use one of those functions (gmw_gf_add_location) to make sure the post is handled by GeoMyWP and put into the seperate database table.
define(‘GMW_GF_PATH’, plugin_dir_path(dirname(__FILE__)) . ‘gmw-gravity-forms/’);
include_once GMW_GF_PATH . ‘includes/functions2.php’;
add_action(‘pmxi_saved_post’, ‘gmw_gf_add_location2’, 10, 2);