How to Toggle Readonly on Child Table Specific Row

I want to make field standard_rate in child table readonly based on another child table field.
I try this code :
frappe.meta.get_docfield(“Resource Item”, ‘standard_rate’, = 0;
but it make readonly for all row in child table.
i want to make just specific row readonly…any help?

I find the solution :
var grid_row = locals[cdt][cdn];
$(“div[data-idx=’”+grid_row.idx+"’]").find(“input[data-fieldname=‘here field name of child table’]”).css(‘pointer-events’,‘none’);