Auto updated chart

Hi

I am trying to have and auto updated chart. I want to add a new date (in row A) and a new value (in row B) every time I open my excel file. But I don't want to have and ex. =(K22) in the cell that goes to the chart. This will influence the chart before the data has been added.

What I want is a kind of "send value to" function. So that the cell which send info to the chart is empty untill it is auto-updated.

Something like cell K22 has the following function (=Send"23.10.2007";(A23))
In this case cell A23 will be empty until this function is activated through an =if function activates cell K22

-Trygve