While that is easy in Producer (using keyframes), the only way I can think of doing it in Gold is to create a slide with the first caption on it. Duplicate that slide and add the second caption to the second (duplicate) slide and use a crossfade between the two slides. Adjust the slide times for the desired effect. Same basic way you create a slide that zooms to a certain level then holds for example (use 2 slides).
You can't have too many gadgets or too much disk space !!
mikey (PSP6, Photoshop CS6, Vegas Pro 14, Acid 7, BluffTitler, Nikon D300s, D810)
Lots of PIC and Arduino microprocessor stuff too !!