A mask for placing horizontally next to other blocks

### The Problem

There doesn't seem to be a brush mask for placing blocks next to another certain block type.
The mask for placing above or below certain block types is simple and works well, but there is no simple equivalent for horizontal placement.

### A Solution

A mask command, where the user specifies an x or z coordinate to place blocks in that direction relative to a given block type. perhaps both coordinates can be used at once for both directions at once placement.

### Alternatives

There may be an expression that can do this, but after extensive searching online, I have not found such an expression, and I have no idea how to make one that will do this.

### Anything Else?

_No response_