As both your source and target data resides on the I-Series you shouldn’t have too much trouble.
We have experience of replicating data between i-Series and MS-SQL using a product called Scribe Insight.
This allows you to map source files and fields to target files and fields. This mapping process allows you to perform functions on source data to ensure it is in correct format for target file. You can also perform lookups on other files where you are changing data records or creating new ones using a mixture of old records.