mergefield within includepicture

[simotomaton]

I have been pulling my hair out trying to get a dynamic image to work in my merge. I've looked at numerous online 'answers' but have not had any actually work. This is my current code based on macropod's super helpful posts.

{ IF { INCLUDEPICTURE { IF TRUE "\\\\server\\images\\{ MERGEFIELD Area_Code}.emf" } \d} {INCLUDEPICTURE { IF TRUE ""\\\\server\\images\\{ MERGEFIELD Area_Code }.emf" } \d} }

But I'm still getting "Error! Unknown op code for conditional." when I run my merge.
It has been tricky to test, as my merge is run by an application I use at work which generates the merge data on the fly, then sends the result to a printer (or pdf).

My image source is a network address. I don't have access to the local drives the software that is running the merge is on. I have tested that it has access to the network location using a direct link (ie no mergefield in the filename).

All my {} are created with Ctrl+F9.

Any help would be amazing, otherwise I'll be back to using 44 different merge templates, one for each area