$status = "processing";

# write first message with -NoNewLine
write-host $status -NoNewline;

foreach ($i in 1..3) {
  sleep 1
  $status += "."
  # Write All updated messages starting with carriage return (`r) and -NoNewLine
  write-host "`r$status" -NoNewline
}

# To append a final message, exclude -NoNewLine
write-host " complete!";