JTS-ACW removing units from campaign

[grognardgames]

Hi all,

I've recently got hooked on the JTS ACW series.  I am playing a campaign and have a question that I am having trouble finding an answer.

I know the command to remove units from map is usually used for exit hexes.  However, the option exists whether they are on an exit hex or not.  

My question is this:  In CAMPAIGN mode, am I able to remove from map and then get the units back later in the campaign as reinforcements, or is the unit gone for the remainder of the campaign?

Thanks in advance.