Link SHA1 in a commit message to custom URL

[Gintautas Sulskus]

Is it possible to override the default linker to link SHA1 in the commit message to a custom URL?

For example, the following SAH1 in the commit message of ProjectA should link to ProjectB:

"This is ProjectB-commit: f0b3312f8ac2d6984d2cd6b94d16c89790d2ba73"

I can capture the values with the following regex:

(ProjectB-commit: )([0-9a-f]{5,40})

But bitbucket never creates a link. The SHA in the message still points to ProjectA