Freezes the first column or columns of the current worksheet.
| Name | Type | Default | Description |
| count | Number | 0 | Optional number of columns to freeze, or zero to unfreeze all columns. |
builder.CreateFile("xlsx");
var oWorksheet = Api.GetActiveSheet();
var oFreezePanes = oWorksheet.GetFreezePanes();
oFreezePanes.FreezeColumns(1);
builder.SaveFile("xlsx", "FreezeColumns.xlsx");
builder.CloseFile();