how to remove a restriction enzyme recognition sequence

I am trying to write the following function

rebase_hassite(S, AG^CT)

I want to remove all the carrots. I already have a regular expression written and now want to remove the recognition site.

My regular expression is as follows: function [ output_args ]=parserebase(file) fid=fopen(file); if fid<0; error('failed to open');end s=fread(fid,'*char')'; regexp[s,'<1>(?<Enzyme>[^ \n]*)[\n]+<2>(?<prototype>[^\n]*)[\n]+ 3(?<microorganism>[^\n]*)[\n]+<4>(?<source of microorganism>[^\n]*) [/n]+<5>(?<recognition sequence with cleavage site>[^\n]*) [\n]+<6>(? site[^\n]*)[\n]+<7>(?<commercial source>[^\n]*)[\n]+<8>(? references[^\n]*)[\n]; end

I am using the following site: http://rebase.neb.com/rebase/rebase.f9.html Number 9.

If this is unclear please let me know and I will try to reword what I am asking.