A0 is so called non-breaking space. While it may (should) be possible to make SAP Spool system to recognize and process them as "normal" spaces (on our SAP_BASIS 740 SP 12 system the preview is already correct, for example), if there is no valid reason for having them, instead of trying to fix the output, I'd try to find out where are they coming from and fix them at the source - migrate the descriptions for example. CL_ABAP_CONV_IN_CE=>uccp( '00A0' ) call returns non-breaking space as character.
cheers
Jānis