Getting rid of the apostrophe in a message

Hi I am getting realtime data from the net, and I amble to get
the number I need but it is inside apostrophe. I want to pass this number to a integer or a float but as long as I have the apostrophe it is impossible.

simple example -
how to I get 80.0 in the float box?

I tried using regexp but it escapes me how to accomplish this task.

I appreciate the help.

thanks