Hi,
Is this using reports or the API?
if you are using the API, just call SetCellValue with a string:
xls.SetCellValue(1,1,”1”); will enter the string “1” into cell A1.
xls.SetCellValue(1,1,1) will enter the number 1 into cell A1.
You might be confused by “SetCellFromString”, which is a method that explicitly does what you are sayin: if you enter the string “1” it will convert it to a number. But SetCellFromString is for particular cases, you should normally use SetCellValue, and pass a variable/constant of the appropriate type as cell value.
If you are using reports, make sure that the database fields or properties used in the reports are strings, and they will be strings too in the final report.