I have a pattern that uses lookarounds to ensure that the captured string is between two other strings

so in other words for the subject string

```
xxxcabyyy

```

my regex looks like

```
String myregex = ((?<=xxx)cab(?=[y]+))

```

so I want to use this regex more than once, because I may be looking for something else like

```
(test string) xxxcabyyy

```

I want a regex that is like 

```
"\(test string\)(?=" + myregex + ")"

```

to say find "(test string)" that comes before whatever my regex matched.

This doesnt seem to work exactly right and i think its beacuse I have lookarounds in my regex that I am now embedding in the lookforward...what can I do to correct this situation?