foreach for field names or custom th rendering

Do we have attributes foreach for column names?

I would like to use display or not some columns based on parameters.

There is two approaches: to use filtering by parameters or by fields, but neither of one is working if they ar outside foreach. This is the case for column names.

f.ex.:

<th frx:if="{reg}">Region</th>
... foreach ...
<td frx:if="{reg}">{reg}</td>

In this case

hiding are not working, because are not using foreach for column rendering because foreach works for block records.