Thanks - I already have a solution to place needed data)
About 50% of the coding/testing is done.
My problem is adding a "Require SoD_SP" option for mapmaker. I have not yet found a way to add data in mapeditor that
1 - still allows map to be opened by regular mapeditor
2 - does not allow map to be opened by Heroes3.exe without SoD_SP
3 - data will be saved by regular mapeditor
ACE can solve 1 & 2 - but is not saved by mapeditor - data gets lost.
I guess it's not very important but I keep looking.