Appending internal table which is referenced by field-symbol

Hi,

I have a selection screen field called SP$00005 which is not known until runtime as the field is selected in Adhoc Query (SAP Query) by the user.

In the customer exit I am attempting to write code to default in a range to this field - it is a date field and I want to enter the range 01.04.2007 - 30.04.2007.

As select-options require the appending of the screen field table SP$00005 I need a way of adding an entry to this table.

Please see my latest attempt below which appends the correct value to the field symbol <startdate> but this entry does not appear in the internal table SP$00005 when stepping through at runtime.

Can anyone suggest a possible solution?

Thanks,

Alan

data: ref_field(8) type c.

field-symbols: <startdate> type table. "table = STANDARD by default

types: begin of sp$00005, "type definition required for syntax check

sign(1),

option(2),

low type d,

high type d,

end of sp$00005.

data: lt_ref type ref to data.

ranges: selection for sy-datum.

ref_field = 'SP$00005'.

create data lt_ref type table of (ref_field).

assign lt_ref->* to <startdate>.

• assign (ref_field) to <startdate>. "- raises type error

move 'I' to selection-sign.

move 'BT' to selection-option.

move '20070401' to selection-low.

move '20070430' to selection-high.

append selection to <startdate>.