edit lock expression

Please refer the below tabular description, we want customer forecast override quantity as below.
Is it possible to achieve this requirement (To-Be) process in Demantra?

AS IS - current solution say 19-Feb-2012 is current bucket

mdp_matrix series sales_data series sales_data series
Date CF Receipt Date Customer forecast Customer forecast override Qty
1-Jan-12 23-Jan-12 Non-editable
8-Jan-12 23-Jan-12 Non-editable
15-Jan-12 23-Jan-12 Non-editable
22-Jan-12 23-Jan-12 10 Non-editable
29-Jan-12 23-Jan-12 20 Non-editable
5-Feb-12 23-Jan-12 30 Non-editable
12-Feb-12 23-Jan-12 40 Non-editable
19-Feb-12 23-Jan-12 34 Editable
26-Feb-12 23-Jan-12 43 Editable
4-Mar-12 23-Jan-12 23 Editable
11-Mar-12 23-Jan-12 23 Editable


TO BE –Reqd solution

mdp_matrix series sales_data series sales_data series