Hi Vinod,
I think we are missing out something here. To reiterate the situation:-
1. Three transaction types exisit now. 102, 103 and 105.
2. 105 will be posted immediately i.e on 31.12.2012 since it represents the premature cash flow. You can do TPM18 for this and hence the gain/loss as per that day's rates will be calculated.
3. 102 and 105 will be posted on 31.03.2013. Valuations performed on them through TPM1 will be nullified since they are offsetting positions.
Hence, if you realise there is no actual valuations to be done from 31.12.2012 onwards.
Please let me know if you want further clarification.
Regards,
Rohit