Unable to Load DLL

Hello Geeks,
 I am developing a project that is dealing with CCTV camera made in china. I am provided by some DLLs from the company. Now i want to consume that dll into my application. I have tried default Visual studio's ADD REFERENCE features. then I have tried tlbimp.exe but it doesn't work.
here is the link of one of the dlls http://saltindia.org/camsearch.dll
I have search a lot about dll, some says "Check the dll header" and CLI Header. I opened this fine in notepad and I found only like "This will not work in DOS mode...". what to do next. Is there any way I can consume this file in .net.
I have already tried to add it as reference in Visual Studio 6.0 VB. even it says this is not a valis library.
Still dumpbin.exe is listing the function inside that dll.
I am confused about this scenario. Please guide me what to do with thi.
Thanks in advance