Initial upload of Organisation model in CRM standalone implementation

Hi,

I am implementing CRM standalone and I need to create Org structure which is 4 tier and has more than 100 org units. Since there is no backend SAP R/3 I need to upload the structure in CRM thru flat file. Now I coudnt find any BAPI to upload the org structure and when I am using BDC it is not able to assign one Org unit to the higher one .

Kindly suggest me some wayout in this otherwise the whole structure needs to be created manually.