It can be
Declare Sub InitDebug Lib "c:\my.dll"
(ByVal thePath As String)
Microsoft Support. How To Write C DLLs and Call Them from Visual Basic
http://support.microsoft.com/kb/106553More:
Writing C DLLs for use with VB
http://sandsprite.com/CodeStuff/Writing_A_C_Dll_for_VB.html