You use 6 columns:
Domestic nongov't domestic currency account
Domestic nongov't foreign currency account
Gov't domestic currency account
Gov't foreign currency account
Foreign domestic currency account
Foreign foreign currency account

An export transaction would then be (assuming the foreign trade is transacted in foreign currency):
Domestic nongov't domestic currency account
+Xphi Domestic nongov't foreign currency account
Gov't domestic currency account
Gov't foreign currency account
Foreign domestic currency account
-Xphi Foreign foreign currency account

And since the domestic sector does not wish to hold foreign currency, it will engage in an FX transaction with the domestic CB:

An export transaction would then be (assuming the foreign trade is transacted in foreign currency):
+X Domestic nongov't domestic currency account
-Xphi Domestic nongov't foreign currency account
-X Gov't domestic currency account
+Xphi Gov't foreign currency account
Foreign domestic currency account
Foreign foreign currency account

Similarly, if the gov't wants to build strategic currency reserves, it will engage with the foreign sector:
Domestic nongov't domestic currency account
Domestic nongov't foreign currency account
-X Gov't domestic currency account
+Xphi Gov't foreign currency account
+X Foreign domestic currency account
-Xphi Foreign foreign currency account

But since the foreign sector does not wish to hold domestic currency in non-negligible amounts, it will close out its transaction by dealing with the domestic private sector:
+X Domestic nongov't domestic currency account
-Xphi Domestic nongov't foreign currency account
Gov't domestic currency account
Gov't foreign currency account
-X Foreign domestic currency account
+Xphi Foreign foreign currency account

This picture represents the net positions. You can further split each column into a full balance sheet. Which you should if you want to discuss foreign stability, because the (strong) foreign account stability condition for a non-hegemonic economy is that neg gov't long FX position exceeds the private sector's gross short FX position and that the current account is not in deficit.

- Jake

Friends come and go. Enemies accumulate.