make google app script start in a certain row code example
Example 1: google sheets get ranges
//getRange(row, column, optNumRows, optNumColumns);
Sheet.getRange(1,1,1,12);
//row --- int --- top row of the range
//column --- int--- leftmost column of the range
//optNumRows --- int --- number of rows in the range.
//optNumColumns --- int --- number of columns in the range
Example 2: google script get sheet size
// This example assumes there is a sheet named "first"
var ss = SpreadsheetApp.getActiveSpreadsheet();
var first = ss.getSheetByName("first");
Logger.log(first.getMaxColumns());
// getMaxColumns() returns the current number of columns in the sheet,
// regardless of content.