Long text for materials

Hi Experts,

I have to create a ALV report in which i have to select plant and material no. and it will display short text, long text1, long text2, longtext3. In column long text1, i need to display only 72 char, if more than 72 then in next column long text2 and so on.

While downloading (save in excel) long text should save as maximum 256 characters per cell, if more than 256 char text then in next cell

I dnt no which table and field i have to use for long text.for short text its maktx

Also please tel me how to proceed in this issue, if any code for reference it will be helpful !!!

Regards

Nikhil