During the Import Routine the following Dialog is displayed, note that the default projection is Universal Transverse Mercator
Click the Custom button:

To find the correct Text String for Lambert-93 - click the link to the EPSG Database:
Search for "lambert-93"

We need the Proj4 string - click the link


Carefully select the whole text string and Copy/Paste into the Custom Projection Tool:

Enter the name and Save.
Note that this Lambert-93 projection will now be available as part of the library of projections available in your copy of Perspective:

The Custom Cursor can be used to show the cursor position in Perspective in both UTMs any of the stored projections:

Click the button and select the required projection.