SQLDriverConnect

[DllImport("odbc32.dll", CharSet = CharSet.Unicode, SetLastError = true)]
public static extern int SQLDriverConnect(
   IntPtr hdbc,
   IntPtr hwnd,
   IntPtr szConnStrIn,
   short cbConnStrIn,
   IntPtr szConnStrOut,
   short cbConnStrOutMax,
   out short pcbConnStrOut,
   SQL_DRIVER_CONNECT fDriverCompletion
);

Microsoft documentation: Link