InfoPath Dev

I have a browser-enabled InfoPath 2007 form that writes 5 fields to a SharePoint list via Nintex Workflow (our farm admins do not have webservices working or I would have used that method and not have this question). In another section of the form, I need to query the SP list and have the ability to select an item from the drop down and then auto-fill the other 4 fields.

Below is an example of what the SP list looks like and what my dilemma is...

Part A - part number S901 - color blue - series 15 - serial number 98760
Part A - part number T901 - color blue - series 15 - serial number 87558
Part B - part number 23A9 - color red - series 13 - serial number 14895
Part C - part number FL15 - color blue - series 15 - serial number 55741
Part C - part number HW28 - color yellow - series 13 - serial number 99974

"Part" is the driving force in the drop down list. When a user is viewing the list to select the item, I need all 5 of the fields visible so they select the correct one ("Part", "Part Number", "Color", "Series", "Serial Number"). As you can see, there can be several of the same Part, Color and Series numbers. I am not sure how to accomplish this without using a web service. I am able to use Nintex and SharePoint Designer workflows if needed. We are on SharePoint 2010 and I am trying to get InfoPath 2010 but for now I am stuck with 2007. Any help is greatly appreciated!!

What about adding a calculated column to the list? You could use that for the description in your drop down.

Thank you Hilary for that suggestion (which I had not thought about)! However, I am not able to pull a calculated field in from SharePoint (or at least not using InfoPath 2007). Please correct me if I'm wrong on this or there's another way around it.

Oh - that's too bad - in IP 2010 / ShP 2010, I could select my calculated field. I bet if you use an owssvr.dll data connection you'd be able to get the value of your calculated field. Here's some help on that.

I don't understand what the problem is with our farm, but I know it is not right and that's very frustrating!! Talking to the company that admins it is is hopeless so I'm always trying to find work-arounds.

I was over-thinking this and I just got it to work with your suggestion! I have the calculated column working and then I added a workflow to set the value in another field to equal the calculated column and voila...that field is now an option in IP07. Thanks Hilary for making me step back and start simple again. Now on to tackle the next part of this project.