Hello Everybody

I have to extract special lines from a textfile.
I know how to read the file line by line into a string.
But i don't know how to search for regular expressions within a line?

Example:

xxxxxxxxx from="xyz@aabca.com" to="aaa@bbb.com" xxxxxxxxxxxxxxxx
xxxxxxxxx from="xxxyz@adddaa.com" to="abab@xyz.com" xxxxxxxxxxxxxxxx
xxxxxxxxx from="xyyyyyyyz@aaa.com" to="aaa@bbb.com" xxxxxxxxxxxxxxxx
xxxxxxxxx from="xyzzzzz@aabca.com" to="aaa@bbb.com" xxxxxxxxxxxxxxxx
xxxxxxxxx from="xzzzyz@aaa.com" to="aaa@bbb.com" xxxxxxxxxxxxxxxx

Now i wont to extract all lines with from="*@aaa.com" &&our special customer
or to="*@bbb.com" &&our special partner

In this exampel * = all emails from the domain

Any help welcomed
Best regards
Albert