how can i update Matrix (order lines) by datasource

hi,

i want to update some values in order lines (quantity and user fields).

There are many problems:

1. odbdatasource.setvalue("quantity",0,200) is not possible

2. i can change the value by using omatrix.columns.item("11").cells(irow).specific.string=200,

but the availability check is coming up.

3. if i fill user defined values in my matrix, i have to display these fields (i hoped that this would not be necessary if i can set the value by datasource)

thanks

Markus