Is it possible to adjust the added header position?

Help!
1

I used add-header in config but if cookie value is very large we can’t capture added header
because our IDS is not enough buffer.

In conclusion, I want to add header before cookie header. Is it possible?

2

I found solution myself.

I setted it up as below

http-request set-header xff %[src]
http-request set-header cookie %[req.hdr(cookie)] if { req.hdr(cookie) -m found }