Suggestions for bulk edit of multiselect field?

Suggestions for bulk edit of multiselect field?

Hi everyone, I only started using Zoho yesterday, and I love it! I hope someone can help me with this (or suggest something else I could do instead).

I'm making a marketing campaign tracker. So I have a list of customer and a list of campaigns (several customers are linked to each campaign). The only way I can think to do this is by using a multiselect field (or checkboxes). That's fine if I'm adding customers to a campaign one-by-one, but if I want to add a whole heap of customers to a campaign at once, I could do a bulk edit.

Problem is, if they already have anything selected, what I choose in the bulk edit REPLACES the selections for the customer. I need it to ADD to the existing selections.

Can anyone please give me a hand??

Thanks heaps.
Simon.

** Posted again in correct category **