before copying a block(s) with duplicate name use the "ren" command to rename all the blocks, if applicable you can use the "Rename to" to add a prefix on multiple blocks.
existing block name "TREE1"
rename to "9-12-01_*"
this will create the new block name as "9-12-01_TREE1"
If the wildcard is used you can rename all the blocks and preserve the original name.