We are looking for a cheap !!! product that can manipulate dial tones into other dial numbers.   For example we want to dial #123 (or any other pre-configure string) and the product will manipulate the tones into new number(such as 00123454678). This product/unit should be installed between the telephone and the wall box.   We would like to get the approximate price for 100/1,000/10,000 units ?   regards