You can hide it by putting a condition on the column of type PL/SQL Expression and using the following as the expression:
NVL(:REQUEST,’MY_REQ’) IN(‘CSV’,’XLS’,’PDF’,’XML’,’RTF’,’HTMLD’)
That will check the APEX bind variable “REQUEST”, and if it is CSV, XLS, PDF, XML, RTF or HTML then the column will not be shown!
More info
To stop a column from showing up for an email, you can use the following:
NVL(wwv_flow.g_widget_action, ‘MY_REQ’) != ‘SEND_EMAIL’