If you have a fairly recant version of Monarch you could try a floating trap which should work providing you always have the same number of fields defined on the line. (If not it might get a bit trickier).
I Suppose it is possible that the curly brackets might cause issues. You could use the MSRP utility to change them to something else. (Or an editor of course, but MSRP is likely to be faster.
Or you could bring the entire line into Monarch (assuming it would not be too wide for the version you are using - 1000 chars for most versions up to V7 if memory serves, 4000 for V8 - and then split the large field into smaller ones using calculated fields. Perhaps manipulate the field type identifier first with something like the REPLACE function (V8) and then perhaps the LSPLIT or RSPLIT functions to extract the fields from the whole-line field.
There are a number of possibilities. Which is (or are) the most appropriate is rather dependent on the what your target output is (an maybe which version of Monarch.)
HTH. I will be happy to answer any followup questions.