If you are using email collecting and want to be able to retrieve information from the body of the email and insert this into a specific field you can use a calculated field and the snip() function to retrieve data as long as there is some standard format in which the data is received.  For Example; you might want to retrieve a order number from an email and insert this into a field.  To do this you would follow these simple steps:

1. Setup collection on the email address.
2. Create a new calculated short answer field
3. Use the formula snip(Body,"Order Number"," ")