You need a unique CodeField and a field that will relate to the code field .. ex Code_Lookup
Relationship = Code_LU //you name it this at creation of the relationship
YourTable::CodeField to YourTable::CodeLookup
The field where you want the data from the calculation field is defined as a lookup using the Code_LU
When you enter a code into the CodeField the Calculation data is entered into the filed you have defined as a lookup.
Lookup can be dangerous because user Z comes along and accidently change code from 11 to 111 and Bam! the data changes.
Another way is to define as a text field with a calculated value (calculation_Field) with the option Do Not Replace existing value option turned off. As the calculation changes , so does the text field.