Automated email rules, processor

I get an automated email from the USGS regarding earthquakes in my area, Hawaii, and want to know of an automated email system to filter, then reparse the email out to a specific email address or directly to a twitter post.

What I get from the USGS has this in the subject line:

2010-05-18 08:19:59 (Mcd 3.5) ISLAND OF HAWAII, HAWAII 19.3 -155.2 (3e1d7)

Right now I have a filter set in Gmail so it looks for keywords in in the USGS email and forwards that to my twittermail account. This allows me to automatically post a tweet containing this subject line. But it’s a bit obscure as most folks won’t understand what Mcd is or that it’s talking about an earthquake.

But I’d really like it to change the (Mcd 3.5) part to something like - 3.5 magnitude #earthquake.

The action would be something like
replace (Mcd

magnitude #earthquake Hawaii County, Hawaii

So the final output would look like
2010-05-18 08:19:59 - 3.5 magnitude #earthquake Hawaii County, Hawaii 19.3 -155.2 (3e1d7)

This would be a simple action to create but is there an online way to do this? Something that doesn’t require my computer to be running 24/7?