Apostrophe error

Hi.
I have a template in .odt and everything works fine. But when I add an apostrophe (') I get the error "can't found the end of the tag". I have tried to substitute this with the xml entity ' but in this case the .odt produced has error and it is not possible to open it.
Is there some trick or solution to use apostrophes?
Many thanks.

The single quote is a string delimitor for TBS. You can escape the single quote using a second single quote.
Example: [myblock.column;if [val]='it''s true']

Many thanks.
Escaping the apostrophe with another works, but both are showed in the document.
This is my code put in the template:

and this is the result:

I have tried to quote the sentence that I want to show conditionally but I get the quote in the result.
How I can get the sentence with one apostrophe?

Many thanks for your help.

The correct syntax is: