Thanks for all your help guys, greatly appreciated. Have been learning about VBE, and have sort of worked out how to do it. Basically, I write a command in an Excel macro to do the calcs, then another command which runs a macro I set up in Access to import the data, then back repeats over and over. Seems to be working, and though I am sure it's not the most efficient method, it'll be like the hare and the tortoise....