Selecting data €“ when some cells are empty
 

I have a data table where I want to put in a variable set of x's and
corresponding y values.
Because the dataset is variable in size, I cannot use the LINREGR to
automatically calculate the regression, because some of the cells in its
reference area might be empty, because of data lack.
Is there a way I can make the regression function automatically (so that it
only uses cells in the reference area where the is data typed in), so that I
do not have to make the regression every time I have at data point (x,y) more
or less?
Maybe macros can help me?