How to detect, if you are running 64-bit Office

New data type LongPtr is Long integer on 32-bit systems and LongLong integer on 64-bit systems, by checking it VarType you can find out on what environments you run your VBA code:

Function Is64BitOffice() As Boolean
    Dim lp As LongPtr
    Is64BitOffice = Not (VarType(lp) = vbLong)
End Function

This trick I learned from fellow MVP Brent Spaulding

Win32API declarations with 64-bit Support

This is an update to older post API calls in 64bit VBA with direct link to large file with Windows API Declarations and Constants for Visual Basic, including 64-bit version.