It seems to me you are going about this the wrong way. I assume the following:
1. Your basic requirement is to produce Work Orders
2. A Work Order can involve one or more Tasks
3. You have a table or list of possible tasks
4. You need to assign specific tasks to a Work Order
The usual way to go about this would be to have a Line Item table which your would use to assign specific tasks to each work order. To achieve this you would have three FM tables: (1) Work Orders; (2) Tasks; (3) Work Order Tasks.
A direct relationship between Work Orders and Tasks would be a many-to-many join (each work order could have many tasks; each task could be performed on many work orders). The third table handles this by functioning as a join table to create specific records each of which represents a single task assignment to a single work order.
Nothing in your screenshot says "tasks" so that makes it harder to answer. Sometimes it helps to label things exactly like you think about them so that we don't have to make assumptions.
I'm assuming that you mean on the right hand side where category1, 2 and 3 are tasks?
Usually numbering fields sequently like this is a clear indication that they do not belong in the table that you've put them in but that they need to be related records. Then that "create work order" section becomes a portal that shows tasks and lets you create tasks.
That does not solve your 'value list' question but gets you on the way with a proper database structure.
Sorry about the labelling, thank you for the advice it makes sense.
Are you able to point me to an example to help me visualise the portal option.
Portals as a view into related records are extremely fundamental, as is recognizing 'entities' in your narrative and translating those in their proper tables. I would strongly suggest getting the FTS Advanced book (it is very cheap) and working through the exercises. Things will very quickly fall into place and much better than we can teach in this forum format.
Thank you for your advice, I have bought the kit now.
Have a nice day everybody.