open saved form or link existing forms

[brandon]

Question: I want to open an existing, filled-out form, from another form's
listbox.

1st Form: I have a form that users fill out and save to SharePoint. Each has
a filename is prefixed with a section title, name pulled from a field on the
form, and appended with a date. These are available in a SharePoint form
library.

2nd Form: I have another form that looks up, filters, and displays the first
form's title in a listbox, and the SharePoint ID field is set as the value.

I have a button on the 2nd form that I want users to click to open the
selected form being displayed in the listbox for editing.

I can pass the ID value to the code or any other field's data, but it seems
that InfoPath is looking for an actual filename in order to open the form,
but it looks like all that I have access to is the SharePoint ID field -- how
do I reference that ID field to open the form?

This is what I have, which works if I know the filename:

var userOpenFile
var objXDoc

userOpenFile = XDocument.DOM.selectSingleNode("//my:RFQLookUp").text

objXDoc = Application.XDocuments.Open("http://companyweb/rfqs/rfqlists/" +
userOpenFile)

RFQLookUp is the listbox where the SharePoint ID field is the value.

Thanks in advance for your suggestions.
Brandon