Stumped on the comment

I have tried every combination I can think of and every search in google that is even close and can not figure out a fix for the issue.  Basically I want to add position for the map grid in comment in xml.  But the xml comment won't evaluate variables before outputting.  You can do it with normal xml output for some reason the commenting wont allow you to.  So I can't add x and y grids to my map to make it easier to read.  So I am asking for help.  Here is what the code and output looks like:

Any help would be appreciated.

Daisy