Converts a text string to proper case: the first letter in each word to uppercase, and all other letters to lowercase.
| Name | Type | Description |
| arg1 | string | The text enclosed in quotation marks, a formula that returns text, or a reference to a cell containing text to partially capitalize. |
builder.CreateFile("xlsx");
var oWorksheet = Api.GetActiveSheet();
var oFunction = Api.GetWorksheetFunction();
oWorksheet.GetRange("A1").SetValue(oFunction.PROPER("dAVID CONNOR"));
builder.SaveFile("xlsx", "PROPER.xlsx");
builder.CloseFile();