That is absolutely not possible.  I'm afraid I still don't understand the
purpose/function of the subform, so I can't suggest an alternative approach.
However, you may be using the wrong tool: if you are trying to perform some
kind of financial analysis or make some kind of chart, you might be better
off in Excel, it isn't really what Access is for.  Or, investigate the
PivotTable view of an Access form, which is a bit of an Excel-type thing but
not as good as Excel.

Dear Baz,

In my database I have these tables:

1) expense_code - fields: expense_code, expense_description
2) profit_center - fieds: profit_center_code,
profit_center_description
3) period - fields - fields: period
4) expenses_control: expense_code, profit_center, period, values_USD

I made a relationship between the fields in the three first tables
with the last table, the name of the fields are the same.

Then I have tried everything to do a form/subform to update/include/
exclude values in my table expenses_control (since Mai/07!). My
problem is that I need that the form/subform has this layout (more or
less an Excel´s sheet):

Form:
profit_center (combobox): the user will select the profit center
period (multiselect listbox): the user will select as many dates as he
wish, and for each date selected will appear one column in the subform

Subform:
expense_code     first date selected    second date selected  third
date selected ...
salary                           100
110                              120
taxes                             50
60                                 70
.
.
.

Is it possible?

Thank you.

André.