How to transfer existing field values to another field?

[MLMike25]

In our org, there are approx 200 accounts with a value entered into a custom field.  It would be great if I could enable the "external ID" setting for this custom field, but apparently I cannot since the field has been created. 

If I recreate the custom field (with "external ID" set),  how can I transfer the values from those 200 accounts to the new custom field so that I don't have to re-enter those values manually? 

Or, if anyone can recommend a better way to handle this, I would greatly appreciate it.  Thanks.  

[Peanutman]

Hi MLMike25,

There a probably a few ways to do this. Here is what I would do (assuming you are on Enterprise or Unlimited Edition).

1. I would create a Report with the Salesforce.com Account ID as well as the value in the filed you are going to get rid of. Be sure to include all ~200 records in your Report.

2. Go ahead and create your new field.

3. Open up the Excel file and change the column name from the old field name to the new field name and save your file as a CSV file.

4. Use the Data Loader and update the Account object to push the 'old' value into the 'new' field.

5. You can then delete the old field since all the values from the 'old' field are now in the 'new' field.

Good Luck,

Eric