If I were you I would try to modify on of the existing Title block library parts.
Bring up the "Edit GDL Library Parts" toolbar by right clicking on the standard Toolbar and selecting it from the appearing list.
Then use the Open Object by Subtype command.
In the appearing Dialog you can select the subtype you want to edit.
Select the General GDL Object\Drawing Symbol\Drawing Title\Built-in Drawing Title and click OK. (Or you can use the Create Clone command).
As a first step save it under a new name and then you can start modifying it.
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