Problem with item and Customer master import

Hi Experts,

I am working on sap b1 2005A with apparel one addon.

Requirement : I have to import item and customer master data

In the Exel file i have most of the fields are present in the Import from Excel Interface. But there are few fields like division and season (item master) , Store and Distribution center(customer master) which donot appear ther for me to select them. These fields are userdefined fields that come with apparel one and are to be stored in item and customer master tables.

Could you please advise me on the same.

Thanks in advance,

kanthi.