我做出来了，代码如下：

#include "apdefap.h"
void OnClick(char* lpszPictureName, char* lpszObjectName, char* lpszPropertyName)
{


__object *cn, *rs;
char cquery[200];
cn = __object_create("ADODB.Connection");
rs = __object_create("ADODB.RecordSet");
if(NULL==cn)
MessageBox(NULL,"½¨Á¢Á¬½Óʧ°Ü","",MB_OK);
cn->Open("DSN=WinCCs cripting");
if (cn->State==0)
MessageBox(NULL,"Á¬½Óµ½²éѯÊý¾Ý¿âʧ°Ü","Á¬½Óʧ°Ü!",MB_OK);
else {
sprintf(cquery,"select * from table1 where weihao='%s'",GetTagChar("sousuo_weihao"));//geshihua chaxun zifuchuan
rs->Open(cquery, cn,1);

if (!rs->eof)
{
SetPictureName("Ö÷»­Ãæ.Pdl","»­Ãæ´°¿Ú1",rs->Fields(1));
}
else
{
MessageBox(NULL,"¶Ô²»Æð,ÄúÊäÈëµÄλºÅ»òÕß¹¤ºÅ²»´æÔÚ","²»´æÔÚ",MB_OKMB_ICONQUESTION);
}

}
rs->Close;
cn->Close;


}