Right-click on the toolbar, select "Select Items" from the context menu, browse to your DLL and select it.
To extend the answer to Greg ... To clarify, you cannot add a user control to the tool field if the code for it is in the same project in which you want to use it. For some reason, MS never added this ability, which would be reasonable; you always need to create user control library DLLs every time we want to use a user control. So, to get it in your inbox, you must first create a separate “User Control Library” project (which may be in the same solution!), And then do what Greg said.
Adam haile
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