Hi,
If that's the only thing the PIC will do this may work:
Code:
GEIGER VAR PORTD.0
CNT VAR WORD
ADD VAR WORD
CONTROL VAR BYTE

Start:
  CNT = 0
  COUNT GEIGER, 5000, CNT     'Count pulses for 5 seconds, store in CNT.
  Gosub SaveData
Goto Start

SaveData:
  'Save data to EEPROM here
RETURN
/Henrik Olsson.