First of all sorry about the long post but here goes. I have a customers DB and a Tasks DB. Customers DB has two portals "past tasks" and "future tasks" I used the "smart ranges" technique (http://www.onegasoft.com/articles/smartranges/index.shtml) and it works fine. But I would like to see only the past/future tasks regarding the current record (customer). In order to do so I need to add customer ID to the already complex multikey. That's exactly where I need help. My customerID is in this form (CuID1,CuID2...) Here's the calculation field for future dates portal in the mainDB:

Substitute(Middle(" 0 1 2 3 4 5 6 7 8 9"; (Int(Mod(Date; 10^1)/10^0) + 1) * 2 - 1; 20); " ";"

The general approach is just to concatenate the customer ID to the calculation(s) with a "& CustomerID". The ID needs to go in each line of the multi-key (each part that is separated by a "

Thanks for the quick reply. (I gave you a 5 star rating, You've helped me quite a few times). I just got home from work (It's 18:12 here in Finland) but I'll try your advice tomorrow. Those limitations shouldn't be a problem since I'm only using 7 digits in the datekey due FM having 31.12.3000 as the max date. (heh, not a typo, 12.31.3000 in your format)

Suddenly everything seems so clear...