As per your first question, I suggest you to read this paragraph in the CVI Formatting and I/O Library manual:
'Scan, ScanFile, ScanIn�Asterisks (*) Instead of Constants in Format Specifiers'; inside it you should find the answer to your question.
With regard to option buttons, in CVI there is no native equivalent to this VB control: you will have to do it programmatically by yourself or use this useful instrument driver available in the Development Library: "Independent Sets of Radio Buttons in CVI",
http://zone.ni.com/devzone/explprog.nsf/6c163603265406328625682a006ed37d/2eec01d3aeecea2b852563ff006c1076?OpenDocument
Hope this helps
Roberto