You need to configure something for the receptionists to do a Whisper Page then, which is better than the speakerphone anyway.
Alternatively if they are using the SoftConsole application they can use the 'Send Message' function to put a message on the display (will light the message lamp, give a short ring and show the text on the display).
Or just transfer the call with a call tag. Again the target will get a short ring, see the appearance button light and if they scroll their display see the text from you saying whatever you put in the call tag.
Stuck in a never ending cycle of file copying.