JAVA如何调用vb 写的 dll

我使用jawin去调用dll..测试jawin自带的例子成功,但是调用我自己的就不行.

vb 写的 dll

方法签名:
VBScript code:
Private Declare Function GetHeadXh Lib "MSControlctl.dll" (ByVal tmpXxdm As String, ByRef tmpHeadXh As String, ByRef tmpJxmc As String) As Boolean


我的JAVA源码:
Java code:
package com.gam.cl;

import org.jawin.FuncPtr;
import org.jawin.ReturnFlags;
import org.jawin.io.LittleEndianOutputStream;
import org.jawin.io.NakedByteStream;

public class yz {
public static void main(String[] args) {
try {

FuncPtr msgBox = new FuncPtr("MSControlctl.DLL", "GetHeadXh");

NakedByteStream nbs = new NakedByteStream();

LittleEndianOutputStream leos = new LittleEndianOutputStream(nbs);
leos.writeStringUnicode("701");

byte[] b=msgBox.invoke("G:GG:", 16, nbs, null, ReturnFlags.CHECK_FALSE);
//这个地方的G:GG:应该怎么写呢?或者其它参数.
System.out.println("aa");
System.out.println(b);

leos.close();

} catch (Exception e) {

e.printStackTrace