I created a video to show an easy way to get a dash into a phone number. Really this can be used to insert anything into an existing cell.
Instead of formatting the cell to look like a phone number, I use 4 functions in one to create this new cell. I use the LEFT, RIGHT, MID and CONCATENATE functions.
You just need to use Concatenate as your main function. This function will take pieces of a new cell and put them together into a new one. Then the LEft, Right and Mid functions will pull pieces of the phone number to the new cell.
Have a look at the video. If you have comments on it, please share. Hope this is helpful.