Yes, it is possible. Two possible methods spring to mind.

Method 1: Instead of a checkbox, you could use a Building Block Gallery Content Control where the dynamic content is stored as a building block which appears when the user selects that option from the CC.

Method 2: Add the dynamic content as if it were already visible and then bookmark that range. Next you create a macro that runs when the user changes or exits the checkbox and sets that bookmarked range as either hidden or visible according to the value in the checkbox.

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Andrew Lockton
Chrysalis Design, Melbourne Australia