i just want to know how to the SUM function  works. i need a function
that can combine some cells' value in one grid. for instance, there's
A1:Hello
B1:World
C1:=combine(A1,B1) <---- the value of C! will be "HelloWorld"
and the variants in combine() depends on user's selection  then it can
be like this
+--------------+
| A1 |
| B4 |
| G5 |
| ... |
+--------------+

maybe it will like this? but i am not sure.
function combine(a as range)
for each x in ...
combine+=cells(x).value
next x
end function