English help files are located in :
"c:\Program Files\Autodesk\Autodesk Robot Structural Analysis Professional 2013\RESC\Engineering\help\44"
go to folder and run *.htm file
"...Help was craeted in old technology not supported by Microsoft anymore.
it may not help."
Anyway... strange that help works OK on Spreadsheet Calculator 2012 and not OK for Spreadsheet Calculator 2013 on the same computer.
Assume that Spreadsheet Calculator 2013 was developed by Autodesk team not Microsoft .
Windows 7 x64, Excel 2010 32-bit.