It can not be that complicated?
Go to position x,y on the lcd
2)
Print a character
3)
Wait a while
4)
Go to position x,y on the lcd
5)
Print a spce
6)
Wait a while
7)
Back to (1)
So you need
1)
2)
3a)
The link that UKHeliBob gave; read it and understand it.
3b)
blink-without-delay example that comes with the IDE; read it and understand it.
3c)
If the only thing that your code has to do is blink a character, you can use delay() - Arduino Reference; if it needs to do more (like reading a character from the serial port so it can be displayed) and stay responsive (react immediately), use (3a) and/or (3b).