keep cell range constant when deleting rows

Hi all

This will probably be really simple but thanks in advance for your time and help.

i have a COUNTIF formula with a cell range for example P5:P250, however, i need to delete rows from within this range, when i do this the range drops, eg P5:P249

Is there a way to keep the defined range constant, i seem to recall something about dollar symbols $ but have tried adding these however no joy.

Thanks

Si