先取出对应frame的document，再取想要的元素，给你我写的函数，新人是应该带着进门的……

//框架获取
function GetDocument(Document:IHTMLDocument2;Index:integer):IHTMLDocument2;//框架获取
var frame_dispatch:IDispatch;
framed:IHTMLWindow2;
ole_index:OleVariant;
begin
ole_index:=Index;
frame_dispatch:=Document.Frames.ITem(ole_index);
if frame_dispatch <> nil then
begin
framed:=frame_dispatch as IHTMLWindow2;
result:=framed.Document as IHTMLDocument2;
end
else
begin
result:=nil;
end;
end;

//点击指定位置或名称的链接，或者给指定的名称或序号的元素赋值
procedure GetItem(Document:IHTMLDocument2;Index:String;IsClick:Boolean;State:integer;Value:string);
var IDoc1: IHTMLDocument2;
ielc: IHTMLElementCollection;
ihtml:IHTMLElement;
input:IHTMLInputElement;
TextArea:IHTMLTextAreaElement;
i:integer;
begin
Document.QueryInterface(IHTMLDocument2,iDoc1);
ielc:=idoc1.Get_all;
if(trystrtoint(Index,i))then
begin
if(IsClick)then
begin
ihtml:=ielc.item(strtoint(Index),0) as IHTMLElement;
ihtml.click;
end
else
begin
case State of
0 :
begin
input:=ielc.item(strtoint(Index),0) as IHTMLInputElement;
input.value:=Value;
end;
1 :
begin
TextArea:=ielc.item(strtoint(Index),0) as IHTMLTextAreaElement;
TextArea.value:=Value;
end;
end;
end;
end
else
begin
if(IsClick)then
begin
ihtml:=ielc.item(Index,0) as IHTMLElement;
ihtml.click;
end
else
begin
case State of
0 :
begin
input:=ielc.item(Index,0) as IHTMLInputElement;
input.value:=Value;
end;
1 :
begin
TextArea:=ielc.item(Index,0) as IHTMLTextAreaElement;
TextArea.value:=Value;
end;
end;
end;
end;
end;