Sounds easy enough, give it a try.
Get a filtered selection set of the arc's on the appropriate layer
Get a filtered selection set of the text on the appropriate layer
Loop through the text items
_ get the insert point
_ Loop through the arcs looking for an end point within a specific distance
__ If found put the entity names in a new list & remove them from the selection set
When done do it again with a larger distance number to pick up any text
with the arc on the right side instead of the left side
Convert the new list to your blocks or directly to the leader & text
If there are any arc's or text in the selection sets, do an alert & highlight the items.