If you need 15 char long values in CSV, you can add SPACEs as FILLER to your EXCEL Cell Value, then save it as CSV.

Unfortunately you have to loop through each row to make the changes. High level logic is like :-

For Each MyRow as ExcelRow in MySheet.Rows
MyRow(Col).Value &= " " 'u put 15 spaces
MyRow(Col).Value = MyRow(Col).Value.substring(0, 15)
Next

The above code will give you LEFT JUSTIFIED 15 char long CSV Field. If you want RIGHT JUSTIFIED Text in CSV, then CODE will be like (for the filler only)

MyRow(Col).Value = MyRow(Col).Value.Reverse()
MyRow(Col).Value &= " "
MyRow(Col).Value = MyRow(Col).Value.substring(0, 15)
MyRow(Col).Value = MyRow(Col).Value.Reverse()

Looping and string operation will take toll on performance - depending on how many rows you have and computer's power. Thnaks you.