Hi Julia @jgawin
I have made a small workflow to show how to use a Loop and Rule Engine to determine the presence of the currency code in a column. As it is, the workflow only works if the currency code is the only thing in the column. However, this can be changed/improved depending on what else may be present in the column.
You can access the workflow in the hub here:
Please let me know if you need further explanation
Best wishes
Heather