We would need to see your file to understand your situation. You can upload it somewhere, such as 4shared.com and provide a link to it here. :^)
Usually problems such as this point to less-than-optimum structuring.
I think I've figured out how to solve the problem but I should explain. I need to copy the result of the calculation field in a numeric field in the same table. How can i do this?
Again, you provide too little information. :^)
Is the copy taking place within the same record or to another record in the same table? And, if to a different record within same table, how are you identifying which?
Well, one method would be something like this:
# go to the record you want to copy from
Set Variable [ $value ; field ]
# go to the record where it resides (as long as it is within same file)
Set Field [ newfield ; $value ]