How to use linest with variably sized data arrays?

[tahsin.alam]

I have a spreadsheet which loads data for two time series from the
database given a start date and end date. I would like to calculate a
regression between these two series using linest.

The problem is that depending on the start and end date, I might have
different size of arrays to enter into linest.

The first try was to include the largest possible range of arrays
-hoping that linest will ignore empty cells when I am loading fewer
data items - but linest does not ignore empty cells.

Next I tried

linest(resize(range1,datasize,1), resize(range2,datasize,1), 1, 0)

But that gives me different results (what?) than if I use linest with
the exact ranges.

Any ideas?

thanks in advance and please ask for clarification - this is my first
time posting here.

matal