Upload long text for a field

hello experts,

I am uploading the data for open AR items. In that i have to upload the data for long text for one field. From the legacy system the data coming as 4000 charecters for one field.

Can anyone guide me how to upload the data into that specific field........

Field should contain total 4000 chars without splitting the data.....

Please any one guide me how to do it

SRI