Office 2hd excel function help

[Ngayeski]

I,m a new ipad2 user. I just added office2hd. I opened a new workbook and tested the function nor dost. I tried using 3 and 4 arguments (four arg = true) but received error message "arg.". I can find no text help describing the syntax for this or any other function. How do I find function help for this app?