How to determine if Office 2007 Excel is installed?

[thought.contagion]

I need to determine if Excel 2007 is installed.

For Office 2003, we had the component ID for Excel 2003 and could use
the msi.dll to enumerate and that would tell us if it was installed:

iRet = MsiGetComponentPath(sProductCode.Trim, sComponentID, sPath,
iLen)
sProductCode is the Office 2003 Product Code, sComponentID is the
Excel 2003 component ID. sPath would hold the path to excel.exe.

I can not find the Excel 2007 component ID that MSI uses. Does anyone
know what it is?

Or, is there another way to tell (besides looking in the registry)?

Thanks.