Save as Non-Delimited Text File

I need to save an excel spreadsheet as a text file, which will then be fed into a mainframe program. It should not be delimited, so the data will just run together. I have tried all of the available text options and end up with spaces delimiting my file equal to the column width (it appears at least). All of my columns will have fixed length data (column 1=4 bytes, column 2=6 bytes, etc.). I have tried fitting my column to the size of the data, but this also doesn't seem to work--when I save the file it still adds spaces to the end of each 'column'. Any ideas?