if(scrollStartPosition > strlen(myString)) {
Ah yeah i see it now.
Here is the result -
It's working thank you very much 
After you run vfd.short_reset(); i've found you must always use vfd.power_on(); for the screen to display. so i added that to the front of the loop and it's working great.
Next i'm going to buy an RTC and see if i can get that to display on the screen.
This screen was free and it's already becoming an addictive project haha.