How do you write Java the regular expression, please?

For example, I have a text="1-18848475154??? PosRecOwner?? _genesys??? Activity_ID? 1-8 nr2c53??? SRNumber?
1-18850439413??? CountryCode?? 1??????? Primary_Target_EWT?? 22??? The Default
"
I want to match the format string
"????? Activity_ID? 1-8 nr2c53??? "

Then take out the value of "1-8 nr2c53
"
"????? Activity_ID? 1-8 nr2c53??? "Before and after the format string,"??????? Activity_ID? "And"??? "The characters are fixed,
Only the value of "1-8 nr2c53" series is a dynamic variable, now I want to search out the value of the dynamic string,

Please comment, share Java code to achieve the above functions,

The string function getActivityIDValue (string text)
{
//please give code - search Activity_ID behind of the value of the string of text and returns

Return
}


Thank you very much!!!!!