Just a tip to increase getting answers in this newgroup: It is best to ask 20
very specific questions than it is to ask 1 general question that contains
many different questions. People tend to skip over questions that are not
specific or focused enough.

To answer your questions:

- No, there aren't many VB.NET samples out there. You'll have to roll your
own code.

- No, the XSN cannot be generated from the XML. You must see an XSN as a
blueprint that contains all definitions and functionality to create the XML.
Without this blueprint, the XML cannot be generated.

- To create a tab separated string, you need to loop through all the
relevant nodes in the XML for your form and generate the string, using the
field values that are stored in the XML. To generate the XML from a tab
separated string, you'll need to have a record of the XML structure somewhere
and use this to generate the XML using the values from your string.

- Take a look at this article
http://msdn2.microsoft.com/en-us/library/ms788215(office.11).aspx for more
information on InfoPath automation.
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S.Y.M. Wong-A-Ton