I'm new with FM and I'm over my head with this.

I am trying to manipulate the contents of field X. Field X is determined by what is in field Y.

Set Variable [$Location; Bindery::Location]

Set Variable [$TargetField; "Bindery::&"$Location"]

Set Field By Name["Bindery::"&$Location;

***At this point I want to set the contents to

"Bindery::"&$Location & Bindery::CustomerName

Field By Name is accessed successfully but I can't figure out how to manipulate the contents.

Any help would be greatly appreciated.

Field X is determined by what is in field Y.

Then why not make Field X a calculation field?

It looks like you're wanting this:

$Location & " " & Bindery::CustomerName

Or use a simple Set Field to:

Bindery::Location & " " & Bindery::CustomerName

Or just use a calc field as comment suggested, or auto-entry.

But why even do any of this, just to duplicate existing data?

You have FM Advanced, so I suggest using the script debugger and data viewer to help you see what's going on. It's not clear to me from your description exactly what result you're getting or not getting.