Sounds like you are sending data  via a web form. My fist suggestion is
to look at the URL when you manually enter information via the internet
form. Sometimes the ASP page URL appears and you can see where it
searches for your data. Example:
www.webaddress.com//product/product.asp?sku= "your data"

If that is not possible then you need to submit your data via the web
form. To do this you need to set a reference to Microsoft Internet
Controls and create an Internet Explorer Object.

Here is an example of using the object, and sending username and
password data via the form.
Dim IEObj As New InternetExplorer
Dim sURL as String

sURL = "https://Enter Web Address Here"
IEObj.Navigate sURL
Do While IEObj.ReadyState <> READYSTATE_COMPLETE
Loop
IEObj.Document.Forms(0)("username").Value = "Name"
IEObj.Document.Forms(0)("passwd").Value = "Password"
IEObj.Document.Forms(0).Submit

You need to find the name of the user form values and replace the values
seen above. Passing regular data such as stock quotes is basically the
same thing...find the name of the search form field, pass your value and
Submit as shown above.

One technique I use is a bookmarklet that converts the POST methods
into GET methods. In most case, this exposes a useable URL with
viewable query  strings. Or, if you use FireFox, the "Web Developer"
extension has an option to do it.

The bookmarklet is "frmget" here:

http://www.squarefree.com/bookmarklets/forms.html