MIRO: Calculate Exchange rate on change in Translation Date

Hello Gurus,

I have enhanced MIRO "DETAILS" tab with Translation Date (WWERT).  

The requirement is when Translation Date is changed manually on the screen, Exchange is calculated again on Translation Date from TCURR table.

The problem is that there is no BADI/ Exit called when translation date is changed manually.

Please provide pointers to the resolution.

Thank you.

Br,

Maninder SA