
Hi i struggle with adding "Currency Factor" field to Reminder page.
How i can do it simple and quick? Somehow tablerelation or rewrite code?
I think you should describe your business case here. Just adding currency factor to your reminder page does not really add any functionality. If you plan to adjust the amount on the reminder you should do so by adding interest or a fee. If you post a reminder on a different amount that what is posted in your customer ledger entry you will end up with a discrepancy when you receive the payment.
Variation in the currency exchange rates are handled through the currency gain / currency loss functionality.