How do I calculate the parameters for a linear regression?

Considering the equation y=βx+α

the α can be calculated as:

Intercept(series1, series2)

where series 1 is set as the dependent series.

And the β can be generated by

Slope(series1, series2)

where series 1 is set as the dependent series.

For more information, check:

Regression analysis

Regression line