Visual Source Safe Data Cannot Be Accessed Through SQL CLR Stored Procedure

The goal is to address visual source safe database on the network. We have the srcsafe.ini in the network as \ipaddrsrcsafe.ini. Now I create a new VSSDatabase object and call its OpenDb. Well for simple consle app or winform it is ok. But I was running it under Sql server Stored Procedure. It failed for I cannot access the source safe path throgh the COM object.

I know it is because of Windows identity. So I add the following code before I want to open the database, changing the to the WindowsIdentity:
WindowsIdentity impersonId = SqlContext.WindowsIdentity;
WindowsImpersonationContext orgCtx = null;
try
{
orgCtx = impersonId.Impersonate();
VSS_Database = new MVSI.VSSDatabase();
// VSS_Database.ImpersonateCaller = true;
VSS_Database.Open(Path, UserName, PassWord);
}
catch (Exception err)
{

orgCtx.Undo();
throw err;
}
finally
{
orgCtx.Undo();
}


Without the commented line "// VSS_Database.ImpersonateCaller = true", this does not work at all. It just behave like no changes to the windows identity.
However if I add this code, well, OpenDb will result in a No-response query. The Sql server is running the query with no responses.
Have you ever met that before? I am really frustrated. Thanks