Make cells readonly for specified data range

Hello all,

For a program we enter start date (01-02-2025)-dd-mm-yyy and End date (31-12-2025), From this range feb 2025 to dec 2025 the cells has to be editable remaining months has to be read only.

I have entered dummy data on flag for the above range using that flag i'm trying to make read only which isn't working.

Here is my code:

def Trend1 = []

def Trend2=[]

operation.grid.dataCellIterator("Payment Terms","BegBalance").each {DataCell cell->

Trend1<<cell.getMemberName("Program");

Trend2<<cell.getData();

}
println("Trend: "+Trend1);

println("Data: "+Trend2);
println(Trend1.size());

println(Trend2.size());
if (Trend1.size() == Trend2.size()) {