Regex expression help

[Voska]

I'm new to Regex expressions and wondering if its even possible to get one to do what i want.  Say i have a string: '2332433Reason:this was not approved'  And assume there are hundreds of rows and maybe only half of them actually have the Reason: part in it.  I'm hoping to use replace in the Regex to turn the column into just 'Reason: this was not approved' 

Something similar to this:

RTRIM(LTRIM(SUBSTRING(Reason_Change_Content, CHARINDEX('Reason:', Reason_Change_Content), LEN(Reason_Change_Content))))

If this is possible can someone tell me how to write the regular expression and replacement text?

Thanks

[Voska · Accepted solution]

Never mind, i just realized there was a typo causing it.  For anyone else that might be looking for a similar answer... seems you can do something as easy as this:

Regular expression: Reason:(.*)

Replacement Text: $1

[Treyson]

For anyone else looking for Regex help, I find this website to be awesome!

http://regexr.com/

[SeanAdams]

:-) another great one is http://regex101.com

Like the site recommended by @Treyson - both allow you to practice and get outcomes in real-time - with explanations etc.