MicroSoft Excel Forecast Formula

I have been using Excel forecast formula to predict price with MT4 data

Its pretty accurate. I need to how to code this formula into an indicator or EA.

Any excel experts out there who knows how to decode the formula used in Excels forecast function

I believe that XL forecast is basically Linear Regression.
Not sure that it is within my capabilities but if you post your XL formulas (preferably the XL sheet) and the data that it refers to then I or maybe somebody else can take a look and perhaps help.