Usage: rotatelogs.exe [-vlfDtTe] [-L linkname] [-p prog] [-n number] <logfile> {<rotation time in seconds>|<rotation size>(B|K|M|G)} [offset minutes from UTC]

Add this:

TransferLog "|rotatelogs.exe /some/where 86400"

or 

TransferLog "|rotatelogs.exe /some/where 5M"

to httpd.conf. By default, the generated name will be
<logfile>.nnnn where nnnn is the system time at which the log
nominally starts (N.B. if using a rotation time, the time will
always be a multiple of the rotation time, so you can synchronize
cron scripts with it). If <logfile> contains strftime conversion
specifications, those will be used instead. At the end of each
rotation time or when the file size is reached a new log is
started.

Options:
  -v       Verbose operation. Messages are written to stderr.
  -l       Base rotation on local time instead of UTC.
  -L path  Create hard link from current log to specified path.
  -p prog  Run specified program after opening a new log file. See below.
  -f       Force opening of log on program start.
  -D       Create parent directories of log file.
  -t       Truncate logfile instead of rotating, tail friendly.
  -T       Truncate logfiles opened for rotation, but not the initial logfile.
  -e       Echo log to stdout for further processing.
  -n num   Rotate file by adding suffixes '.1', '.2', ..., '.num'.

The program for '-p' is invoked as "[prog] <curfile> [<prevfile>]"
where <curfile> is the filename of the newly opened logfile, and
<prevfile>, if given, is the filename of the previously used logfile.