I think the @onwow64 would be a good starting point for that.
I am not really sure why would one want to do a searchreg() though. I have 32bit office 2010 and that searchreg() code above will say I have 64bit just because office 2010 does come with some 64bit components. for the registry route you would need to search for specifically: {9XXX0000-AAAA-XXXX-B000-0000000FF1CE}
where X-denotes stuff you don't care about and B stands for bitness, 1 being 64bit office. the AAAA you need to filter against as you want only the office key, not the individual components, so search for one of the following values in the AAAA field: 0011 Microsoft Office Professional Plus 011D Microsoft Office Professional Plus Subscription 0012 Microsoft Office Standard 0013 Microsoft Office Home and Business 0014 Microsoft Office Professional 002F Microsoft Office Home and Student
