Excel will support Bitcoin in an upcoming release.
According to Microsoft’s roadmap for Excel, Bitcoin support will:
“… track, calculate and analyze Bitcoin data using native Bitcoin number formatting options. Feature is first being rolled out to Excel 2016 for Windows, Excel Online, Excel Mobile for Windows and Excel Mobile for Android.”
What exactly that means remains to be seen. Ideally, it will include a function to grab the latest Bitcoin exchange rate.
Presumably Excel will get Bitcoin to the Accounting and Currency formats.
The Bitcoin symbol is available already in fonts that support the wider Unicode range of characters.
In Office, type 0243 then Alt + X to insert a Bitcoin symbol.
For more info on the Bitcoin symbol see this.