Maybe that rumor came from me.
I know now that there is a "KONVERT" utility that can convert a COMTEXT application. It is ENTRY ID 2022013 on Siemens support site.
Unfortunately I dont know about a similar utility for COMGRAPH.
And there seems to be a problem with searching on Siemens support site at the moment. When it is up and running again, try to search for "COMGRAPH".
If still no success, contact Siemens and explain them your problem.