How to open a password protected excel workbook in TestComplete?

I used the following JavaScript:

var Excel= Sys.OleObject("Excel.Application");

Excel.Workbooks.Open(filename, 0, false, 1, "password");

This script worked, But if I set the "password" string in a variable of type password and I pass it to function Excel.Workbooks.Open(); TestComplete doesn't decrypt the password variable. 

How do I decrypt the password variable or pass it into Open function and in TestComplete docs they mention passing it using only SetText or Keys but that doesn't help in this case.