Load your footage into AVID that was shot at the frame rate 59.94
You can link it or transcode or import it into AVID but notice the frame rate is 59.94

Your Project needs to be 23.98 format

Select the clip you want to effect and right click it and choose "Source Settings"

Choose the "Playback Rates" and change it to Projects FPS (23.98)

Click OK

Now the file will play in slow motion in the project. Edit with it as usual.

You can also transcode the clip if you want and it will keep the slow motion effect

You can change it back by setting the Playback frame rate to 59.94 and it won't affect anything in the time line you used at 23.98