How do I combine multiple java (OpenJDK) buttons into a pile on the taskbar?

Question

I found this answer for Oracle's Java runtime. But I am running ojdkbuild (OpenJDK) which doesn't seem to create the same registry entries.

I have done a search for "isHostApp" & "java.exe" within the registry & have not yet found anything. The ojdkbuild installer does create some entries in HKEY_LOCAL_MACHINE\Software\JavaSoft, but does not appear to be what I am looking for.

I would have just commented on the above question, but I do not have 50 reputation yet.

Edit: I found the following keys & removed "JAVA.EXE" & "JAVAW.EXE" from them but didn't make a difference:

• HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\FileAssociation\HostApps
• HKEY_LOCAL_MACHINE\SOFTWARE\WOW6432Node\Microsoft\Windows\CurrentVersion\Explorer\FileAssociation\HostApps