Variable lenght of data for graphic

[marsss]

Hello, i would like to know if it s possible set variable in a cell or something else that do same job to set the serie selection for a graphic. to explain better i can provide this exemple :

Here the data for the graphic

   A  B
1: 1  2
2: 2  4
3: 3  6
4: 4  10
5: 5  8

SO source data to plot a curve graphix is :

serie 1 : $B$1:$B$5
X axe   : $A$1:$A$5

which give :

10|      *
 8|        *
 6|    *
 4|  *
 2|*
 0|__________
   1 2 3 4 5

what i want is set a variable for the $B$5, so i canenter in juste one cell a value to show only half of graphic, which would give :

   A  B
1: 1  2
2: 2  4
3: 3  6
4: 4  10
5: 5  8

SO source data to plot a curve graphix is :

serie 1 : $B$1:(insert trick here)
X axe   : $A$1:$A$5

trick value $B$3

which give :

10|
 8|
 6|    *
 4|  *
 2|*
 0|______
   1 2 3

is it possible?

in my case i have like 20 curve plotting, and i dont want manualy edit data source in each line each time i insert new data..

 

[marsss]

Forgot to say, i m in Excel XP