call dll function in c# which is developed in vc++

Question

I am having a code which is in c++ and which use source file which is having extension .F90. Now when I am going to build this code I am finding below listed error:

 

Error 1 error RC1015: cannot open include file 'afxres.h'. E:\Projects\PCSWMMforStormceptorSourceCode_my\TSSFOR\tssfor.rc 10 1 tssfor

When I replace afxres.h file with windows.h, I found below listed errors:

 

Error 1 error LNK2001: unresolved external symbol __DllMainCRTStartup@12 E:\Projects\PCSWMMforStormceptorSourceCode_my\TSSFOR\LINK tssfor

Error 2 error LNK1120: 1 unresolved externals E:\Projects\PCSWMMforStormceptorSourceCode_my\TSSFOR\Debug\tssfor.dll 1 1 tssfor

 

This code is developed by someone else so I dont know much about it, But I want to call a function of a dll which is generated from here into my c# application. Please help me out.

 

Thanks in advance.