Comma seperated list of numbers

Hi all

I'm generating an excel report on the fly with data coming from an oracle database. One of the fields in the database is a comma seperated list of numbers. When I try and view this in Excel it is treating it as a number field and doesn't display properly. For example, it displays the first five numbers correctly and then converts everything else to 0. I presume its because its treating it as a number field. When I concatenate a letter on the end it displays fine but I can't do this as this data is being used by another system which requires the field as it is in the database. Does anyone know how I can resolve this. I've tried changing the format of the cell to text but it just displays the number to the power of 74 (1.4214314415916E+74). Heres the list that is being generated by excel.

142,143,144,159,160,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000