You can use Direct Addresses in RSView ME, or you can use RSView ME Tags (these are in the Tag Database) that are then associated with a SLC Address.
Direct Address:
If "H9" is your shortcut name in RSLinx Enterprise, then in the Connection tab for a String Display object in RSView ME you should have your String data element addressed as:
{::[H9]ST12:10}
RSView ME Tags:
If you are using RSView ME tags, you should have a Tag in the Tag Database called "ST12_10" (this is convenient, but you could name it anything) which is defined as a Device Tag with address:
::[H9]ST12:10
In the Connection tab for the String Display object in RSView ME you should enter:
{ST12_10}
If you are doing a String Entry, you use the same syntax in the Value Connection.