The idea behind was to use existing programs, which are able to make a reengenering from existing code like it was done by Enterprise Architect.
So first I tried to extract classes from an exisitng LotusScript library into a file and import that stuff as VisualBasic code into EA. There was no error, but also no generated diagram! Damned, life could be so easy ....

So I tried to import existing VisualBasic code and viola, there was a UML diagramm. Cause the fact, that LotusScript is almost identical to VisualBasic, my thought was that there may only be a few needed changes in the code, to be able to import it into EA.

And really, this was the rigth way. Here are te modifications which had to be done for existing LotusScript code, to be importable by EA:

Comments, which are in front of a method will be also imported as method description.
Inheritance and associations (use of instances of other classes in a class) will be generated.

Export with R5 is a bit tricky, it could be done by create a synopsis, and export the classes with a text editor into seperate files, But be carefull,
Synopsis doesn't export all code, if script libraries reach a specific size (greater the 100 kB)

Export with R6 could also be done be DesignSynopsis, but could be also done by export all code to XML.
So you are able to transform the stuff with XLT into new files quasi automatic.

Example: