[AccessD] How do I calculate the sum numbers of an array

[Kostas Konstantinidis]

Hi again,
I am trying to make a formula calculation to be able to figure out easily 
and faster a unique key indicator very important for my personal usage.
So, I use a field with a generated string like
50 150 22 35 50 68 etc
The total group numbers are 6
The formula calculation I need depends of the result of the total group 
numbers
if the total group is an even number it must sum the even parts of group 
(150+35+68 = 253)
else if it's an odd number it must sum the odd parts of group (50+22+50=122)

I ask for your help another once

thank's
/kostas