I would suggest looking in the tutorials or help files for using blocks to do this
Looks to me like you should use a "Datum Target".
I too am looking for a 'custom balloon' as the version found in ......
Options-Document Properties-Annotations-Balloons-Single balloon-Style:Inspection
..... does not match the 'Google maps paddle' symbol used by the injection moulded parts inspection dept. of our supplier.
When you put the balloons in, you can select circular split line as the balloon type.
That will get you this:
You might have to add the additional text as notes. If you do, make sure you group the note with the balloon so that you move them around together.
It almost seems like weld symbols might get you part of what you want, but I'm not sure you can quite get there with them either.
If you are using SolidWorks, is there a reason why you can't adapt to how SolidWorks uses balloons?
Does it absolutely have to look just exactly like that? (I included a screenshot for the benefit of people that haven't opened the .dwg file.)
In SolidWorks you could have the text portion as a stand-alone note, linked to custom properties in the model (which can save a tremendous amount of time and reduce the chance of errors, especially if this Part is used more than once). Then set up your balloon as a separate annotation, with a split line, as Carrie Ives suggested. After you get the Balloon set up, with the desired links to top and bottom, save it as a Style (see near the top in her screenshot). This way you could apply it to other Parts and the numbers would update accordingly. Or just copy and paste it, but if you save the Style in your Drawing Template then it would be there for future drawings, not just the current one.
The Note could also be saved as a Style, along with the links to the custom properties.
If it does have to appear as one Annotation, with one leader, you could hide the leader for the note, and Group them (again, as Carrie suggested), but getting the text parallel with the balloon leader would be a nightmare.