Hope you are all doing fine. Thanks for the query regarding the FCV.
Please be informed that we have resolved the issue by changing account assignment in KDF
Created a new entry for S.Creditors (130105) and under that assigned in E/R Diff options FX Loss and FX Gain and in E/R Valuation option assigned the above said A/c FX Loss & FX Gain to respective fields and assigned Bal.Sheet.Adj.1 GL to the last column.
Thanks to all for your support and help. Many more queries will follow as i am new to SAP FI / CO.