I have been trying different variations to trade one block with another using VB.Net My block that needs to be traded out is found within a dynamic block. This block moves using dynamic properties therefore it is not possible to open the dynamic block, delete the first block and insert the second one in it's place. The block has to be traded out with it's replacement. It needs to work like the command -insert. I tried using this with the stringtoexecute meathod and this works till I have to do it a second time. I then get an error message because the block I am trying to redefine is already in the drawing. I would be thanklful for any assistance.