Importing large amounts of data


I’m currently using XML to import geo-location data to my flash application.
Even though my XML scheme is about as small as can be, I still feel i would do better downloading the variables as text and exploding them.
If i manage to change the xml to raw text I can compress the data to about 35% of the original size.

I want to load the data in the form a_b_c_d-e_f_g_h.
So, to the question; how do I explode a datastring in flash?