Need ideas for one-off war adventures!

[NRSASD]

My campaign is just firing off the first salvo of a civil war that's been brewing for quite a while. I've got a few adventures blocked out and a few critical moments (big battles, sieges, and the finale) planned, but I realized my PCs aren't quite powerful enough yet. What I'd like is a few side quests that could fit between the main events to give them a bit more xp and treasure, or a die-based war events chart I could take a look at to get a better grasp of the overall flow of the war.

Setting: We have a fairly standard medieval kingdom that just launched into a civil war along North/South lines. The rightful king was kidnapped by the South, but for reasons too long to explain, the North has to pretend the king is still present. The South has accused the North of holding the king prisoner, and is attempting to "rescue" him, but are really just trying to take the Capital. There are Orc-filled mountains to the south that the South has traditionally held at bay, a xenophobic Elven kingdom to the West that has very limited dealings with the North, a couple free city states in the north favoring the North's side, and a Pirate Confederacy in the East which is supporting the South.

The PCs are working for the North and have just silenced a listening post for the South so that the Northern armies can march undetected. They have also secured the loyalty of one of the counties that was previously neutral. What other civil war themed quests could I send them on?

As always, thanks for any and all help!

[Tiktik Ironclaw]

You could probably have the PCs deal with the pirates in some capacity; serve as guards aboard a Northern vessel, get orders to attack a particularly nasty group of pirates, or just assault one of their strongholds.
Otherwise, freeing prisoners from enemy bases or capturing small forts could work, as could searching for some ancient relic of power that could influence the tide of the war. Hope this gives you some ideas.