DLL shared among DLLs

my app runs like this

Main.EXE
|
|-- Acounts.DLL
|-- Customers.DLL
|-- Payable.DLL
|-- Inventory.DLL
|-- Payroll.DLL

the main.exe is the system manager of this program, and there are a log of DLLs works like "Plugins" to the system manager, there is not reference in the Main.EXE to those DLL, i create to object dynamically: -

Set Plugin(x) = createobject("Accounts.Server")
where server is a class in accounts.dll

The problem is: -
i have another DLL which handle the database connection and a lot of other shared function what should be accessable to all plugins DLLs and the Main.EXE, i want to create this shared DLL only once in the Main.EXE, then i want this DLL to be shared among all plugins DLL..

What do you mean by creating a dll in an exe?
Well, if you are thinking of having a reference set to an standard exe, it is not possible. You might try using ActiveX Exe, but then circular reference might cause you problem. Wouldn't it be easier if you create an dll and use its refrence either at design time or at runtime.