#include <MsgBoxConstants.au3> ; to declare the Constants of MsgBox
Local $sRegex = "(?m)([\s\.\,]|^)[^#]\w+([\s\.\,]*?|$)"
Local $sString = "This is a #text, which is #full of #hashtags." & @CRLF & _
"Well, this is not #easy to" & @CRLF & _
"#extract #them. " & @CRLF & _
"I think I #start to lose: #hope."
Local $sSubst = "$2"
Local $sResult = StringRegExpReplace($sString, $sRegex, $sSubst)
MsgBox($MB_SYSTEMMODAL, "Result", $sResult)
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for AutoIt, please visit: https://www.autoitscript.com/autoit3/docs/functions/StringRegExp.htm