Removing Comma's from string in Beast Mode Numeric Values

I have a Beast Mode that I'm using to trim a value from a string, the issue is that the trim contains a comma which prevents me from treating the resulting values as a number and therefore suming the totals.

Here is the Beast Mode that is producing the trim value:

Case When Month(`EventDateTime`)= month(CURRENT_DATE()) and `EventNotes`is not null THEN LEFT(`EventNotes`, INSTR(`EventNotes`, ';') - 1)
else 0
End

Is there another Beast Mode I could use to remove the comma or a way to remove the comma in the above beast mode.

Any help as always appreciated.

Thanks

Randy