[Isis-users] Selection of records by mx

[fred train]

Hello guru's

We are trying to list in a script by mx and a specific pft file.
This works wonderful.
Now we would like to make a selection of the processed record by the 
value of a specific field.
In words : process if field 290 has value OK.

Command mx has a "bool" parameter, which combined with btell=0, looks 
promising.
The manual gives examples like
mx cds "bool=water + soil"

This example does not specify which filed are searched.

How to specifiy that water must be found in field 001 and soil in field 002

Regards
Fred