Wait for string then copy string

[e2script]

Hi,

I wonder what's the easiest way of creating a script that does the following:

1. Script runs a command that I specify in the script.
2. Host returns a string that looks like this: <number>:<number> <word that varies in number of digits> VL_<four digit number>_xxxxxxxx <letter> <letter> <number> <word>
3. Script understands that what we're looking for is the 4 digit number marked in bold above.
4. Script runs a new command that I specify based on that number. ex. sh vlan id <four digit number>

The word VL_ will always be put in front of the 4 digit number.

What's the best way to make a script like this?

Best regards,
e2script