PaulS:
Since you (will) have count as an unsigned long, and since the LCD can print() an unsigned long, it doesn't make sense to print the digits one at a time to the LCD. So, get rid of the loop, call atol() once, and Serial.print() and LCD.print() count once.
I'm printing digits one at a time so that user knows what count he is entering. Wouldn't displaying the count only after pressing the enter key be inappropriate?