Based on my interpretation of your post, you table(s) design is not normalized. You don't add data across in fields (columns) you do it down in records (rows). Sounds like you have used your Excel brain to design your db. If so, it will only continue to plague you with problems. You probably ought to have a table for equipment, which the listbox is populated from, but the rest is a guess. If it's equipment for a job for example, then you'd have a table with everything related to the job details (that does not include equipment and the like) and then a junction table that relates the job data to the equipment used on it. Normalization needs to be the #1 aspect that you get right in a relational database. #2 is normalization. #3 is normalization. I think by now you get my drift!
The more we hear silence, the more we begin to think about our value in this universe.
Paraphrase of Professor Brian Cox.