How can I programmatically convert a topic OID to a GUID?

MM does this nicely in the GUI with the "Copy as Hyperlink" command on the topic context menu, but as far as I can tell, this function is not available through the API. I do not need to create a GUID--I need to convert the existing OID to a guid. Like this:
OID for a topic = "3DLHM/BCokaqGKl/tYq9Qw=="
GUID for the same topic = {33C732DC-42F0-46A2-AA18-A97FB58ABD43}

There has to be an algorithm for this, but it isn't obvious to me. Does anyone know?

In case you're wondering, I need the URL hyperlink to link to a topic from another app. It works great once I get the hyperlink, but I just can't figure out how to get it through the API.

OK--I found my own answer. The OID is a Base64String. You need to convert it to an array of bytes from which you then create a GUID.

In VB.NET, you do it like this:
'Create the GUID from the OID
Dim tGuid As New Guid(Convert.FromBase64String(Topic.Guid))

'Then use this to create an HTML Link just like you get from Ctrl-Alt-C:
Replace("mj-map:///" & MMApp.ActiveDocument.FullName & "#oid={" & tGuid.ToString.ToUpper & "}", " ", "%20")

Hi friends,

I am using Mindmanager 8. I am creating an xml version for the mmap file by using MindmanagerDocument.xml.

MindManager.Application mmApp = new MindManager.Application();
mmApp.Visible = false;
MindManager.Document mmDocument = mmApp.AllDocuments.Open(@"E:\Departments.mmap", "", true);
string docXml = mmDocument.Xml;
XmlDocument xmlDoc = new XmlDocument();
xmlDoc.LoadXml(docXml);
xmlDoc.Save(@"E:\DocMap.xml");

Now I want to add a new Topic node to this DocMap.Xml.I am serializing the MindManager.Topic through Xml Serialization. For this I need to specify the attributes OId,Dirty,Gen and all the attributes. I am not sure on How to generate OID from Guid,Dirty,Gen?

Please help.

R.Saranya.