/SPACE=substitution-character

    This qualifier is valid in conjunction with /DESTINATION=COMMA or
    /SOURCE=COMMA. This optional qualifier specifies the character
    used in the LDIF file in place of the space character in
    attribute names (since space is not a legal character in an LDIF
    attribute name). If the /HEADER qualifier is being used, then
    the resulting "header" line written to the comma-separated output
    file will contain the space character in place of any occurrences
    of the character specified with /SPACE in the attribute names.