Thanks for the response! I don't think this is the desired result, I'll try to do a better job explaining the form (sorry for being vague earlier). I want all these values going into a single list item.
In the SharePoint list, I have a 'Choice' column called "Request Type". That has 28 different options (Market Research, Analysis, Other, etc). They can choose multiple values from that list it they want. Naturally this works fine when using the basic SharePoint list controls.
Now in my InfoPath form, I have a Multi-Selection box that has all these same values. I then flatten all the values into a single comma separated string with the following rule and default value on another text field:
substring(eval(eval(ResearchTypes[. != ""], 'concat(", ", .)'), ".."), 2)
My gut is telling me I am just not collapsing it down into a string correctly but I could be way off.
I then mapped that field to the 'Choice' column in the SharePoint list and it populates the field when you look at it the view, however, when you open the item to edit it, the applicable checkboxes for those Choice items are not selected.
Is it possible to populate a Choice column in SharePoint from InfoPath? If so, how? :) Thanks again for the help! I am really stuck here. I would be shocked if your product doesn't do it, Im hoping Im just doing something wrong/dumb.