Hi Rezvan,
That is not possible also this is not required.
Because unrealized gain/loss we post to Balance sheet adjustment account and Fx gain/loss accounts.
We don't post any differences directly to sub ledgers.
you can use F.05 or FAGL_FC_VAL trasanction for Foreign currency valuation.
where you can have option of valuate the Spl GL too in selection screen.
Also
When you select Vendor option in FAGL_FC_VAL, program valuates all the line items including special gl items.
And this valuation difference can be posted to balance sheet adjustment account which you maintain in OB09.
Regards
Atul