Problem in invoking a dll

Question

Hi All,

I facing a problem which i have described briefly in the following paragraph.

Let me tell you a scenario where in the user has to choose any kind of dll he wants, rather be .Net Dll or Native Dll for a connection to his server.
In that he knows the function to Invoke.

I need to write a common user interface to invoke any kind of dll, based on the choice of the user. Is that possible ?. If so help me regarding the stratergy that i have to use or any examples of such accomplishment.

FYI
I know one software which is doing to most of the Dll's.

Thanks in Advance