Previous Depreciation question

I have an asset that I need to do a partial disposal on.  Unfortunately years ago someone altered some of the months so the system is not allowing a partial no matter what I try.  

I'm going to fully dispose of the asset and then add it back in so I can partially dispose of it.  My question is, I know there is a place to add in "accumulated depreciation before" and "last posting date before import" - as an example:

Asset $6000
Life 60 months
$100/month dep

Say the asset has 30 months left to depreciate when I dispose of it.  

Do I put it back in at:

Asset $6000
Life 60 months
A/D before $3000


I still want my depreciation to be $100/month because technically we only have 30 months left.  Is the system smart enough to know that?