Try it withouth making an array :

turns_required VAR WORD

a BYTE = 8 bits = 0 to 255
a WORD = 16 bits = 0 to 65535

so my understaning is that turns_required would hold a value up to 65535 without issue.

You can do some testing by reading the value in as a DEC with HSERIN and "echo" it back with HSEROUT as a DEC or read the value and blink an LED = to the number you entered. I wouldn't test that at 65535 LED blinks. If you do use an array "turns_required VAR WORD[2]" then you would save and retrieve data from turns_required[1] and turns_required[2]. I don't think you need to do that...

Hope this helps, Good Luck.
Shane