Andrus,

In VFP9 you could use CAST:

SELECT CAST(NULL AS C(3)) as c2 FROM test INTO CURSOR test1 readwrite

>I create RW cursor by selecting constant expression
>I want to store NULL to the created field later
>How to force cursor field to accept null values ?
>ALTER TABLE c2 NULL cannot be used since real cursor contains some hundreds of columns need to allowed nul values and lot of rows.
>
>Code to reproduce:
>
>

CREATE CURSOR test ( c1 char NULL )
>APPEND BLANK
>
>APPEND BLANK
>SELECT  '' as c2 FROM test INTO CURSOR test1 readwrite
>REPLACE c2 WITH null

>
> Observed: program error
> Field C2 does not accept null values.
>
> Expected: no error