Sage 200 Workspace/Action files - where to reference bespoke workspace Actions?

Good afternoon.

In Sage 200 I have written in some linq code previously and i have created bespoke workspaces, however now the time has come for me to put some actions to some of the workspaces.  I know about the IM Modifications folder etc, but if possible, could anyone point me in the direction of pointing the actions to be selectable from the Content part editor?  At the moment, only the default actions are showing which are not good to me.

Many thanks in advance.