ListBox1->Items->Strings[0]=buf1;

TForm1 *Form1;
bool i=0;

__fastcall TForm1::TForm1(TComponent* Owner)
        : TForm(Owner)
{
}

void __fastcall TForm1::Input(TObject *Sender, char &Key)
{
if(Key==0x0D)
{
char buf[256];
char buf1[256];
strcpy(buf,MaskEdit1->Text.c_str());
for(int i=0;strlen(buf);i++)
{
buf1[i]=buf[i];
if(buf[i]==' ')
{
buf1[i]='\0';
break;
}
}
Label1->Caption=strlen(buf1);
if(i==1)
{
strncat(strncat(strcpy(buf,ListBox1->Items->Strings[0].c_str())," ",1),buf1,strlen(buf1));
ListBox1->Items->Strings[0]=buf;
}
else
{
ListBox1->Items->Strings[0]=buf1;
i=1;
}
}
}

ListBox1->Items->Strings[0]=ListBox1->Items->Strings[0]+buf1;