Excel 2007 : Populate Userform Combobox from Pivot Table

I am stuck on trying to get my user form to populate my combobox from a pivot table that I am using. In this userform you are to pick from customer numbers (this is the combobox) that are in this pivot table and then from there pull the rest of there info (i.e slip#, dry tu) into a listbox where they can check which items will go into another sheet. If someone could shed some light on this that would be just perfect. I have attached a sample and if more info is needed I would be happy to provide it.

I thank you in advance for your help.