Using a soft-edged round paint brush in PhotoShop/PaintShopPro/PhotoImpact, draw the words in black on a white background. Use that image as a discriminator mask to control what part of the glass panel is fogged (white) and what part is clear (black).

If you can post (advanced material room) screenshots of the fogged glass material -with nodes expanded- I can be more specific. You'll need to know how the glass is UV-mapped, or test fit images to the glass to figure out the mapping.

Poser 12, in feet.  

OSes:  Win7Prox64, Win7Ultx64

Silo Pro 2.5.6 64bit, Vue Infinite 2014.7, Genetica 4.0 Studio, UV Mapper Pro, UV Layout Pro, PhotoImpact X3, GIF Animator 5