PI SQC Programmer Reference Guide (Sqcvba.chm) can be found at %PIHOME%\Help\en\ on machines with PI ProcessBook 2012 SP2 installed. I didn't find it on a client with a previous PI ProcessBook release installed but confirmed PI ProcessBook 2012 SP2 setup kit, available at vCampus Download Center -> PI Clients, installs it.
You may also be interested in KB00406 - Plotting SQC Attribute Charts Using the PI SQC ProcessBook Add-in.
As of PB 2012, you can get there using Help->PI SQC Programmer's Reference.
OK， I will study them carefully.
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