BleepingComputer.com: Mail Merge Apostrophe

In a mail merge, how do you write the IF statement to deal with the possessive case?

If you are trying to write a paragraph for a mail merge document using the possessive, how do direct MS Word 2007 to use " 's " or simply " ' "? For example, I have 2 names in my data source, Smith and Jones. I want to write the sentence, "[Name]'s bonus will be $500."

For Smith, the sentence reads correctly as, "Smith's bonus will be $500."

For Jones, the sentence uses incorrect grammar, "Jones's bonus will be $500."

It should be Jones' with a simple apostrophe and no "s".

I could deal with the problem in Excel, but I keep getting an updated data source and don't want to continue to edit the spreadsheet.

Any help would be great!
Thank you.

You might be pleased with this:
http://www.bartleby.com/141/strunk.html#1
See also the Chicago Manual of Style, 6.8, where possessives of singular nouns (such as names) are almost always formed by 's, as in Burns's poems.
Cheers,
John