[GOOGLE-SHEETS] method getRange (ok)

https://stackoverflow.com/questions/11947590/sheet-getrange1-1-1-12-what-does-the-numbers-in-bracket-specify

method getRange(row, column, optNumRows, optNumColumns)

Using the example on the docu:

// The code below will get the number of columns for the range C2:G8
// in the active spreadsheet, which happens to be "4"
var count = SpreadsheetApp.getActiveSheet().getRange(2, 3, 6, 4).getNumColumns(); Browser.msgBox(count);

The values between brackets:
2: the starting row = 2
3: the starting col = C
6: the number of rows = 6 so from 2 to 8
4: the number of cols = 4 so from C to G

So you come to the range: C2:G8