Here are the instructions after you go through the fixes in the other thread:
'<!-- Send Welcome PM Message -->
' First lets get the members ID
strSql = "SELECT " & strMemberTablePrefix & "MEMBERS.M_EMAIL "
strSql = strSql & ", " & strMemberTablePrefix & "MEMBERS.MEMBER_ID "
strSql = strSql & " FROM " & strMemberTablePrefix & "MEMBERS"
strSql = strSql & " WHERE " & strMemberTablePrefix & "MEMBERS.M_EMAIL like '" & chkString(rsKey("M_EMAIL"),"SQLString") & "'"
set rs = my_Conn.Execute (strSql)
' This is the string for your welcome PM subject
welcomepmsubject = "Welcome To My Site!"
' This is the string for your welcome PM message
welcomepmmessage = "Place your message here."
' Do not change these
strpmtoid = rs("MEMBER_ID")
strpmrid = "1"
TF = "0"
strSql = "INSERT INTO " & strTablePrefix & "PM ("
strSql = strSql & " M_SUBJECT"
strSql = strSql & ", M_MESSAGE"
strSql = strSql & ", M_TO"
strSql = strSql & ", M_FROM"
strSql = strSql & ", M_SENT"
strSql = strSql & ", M_MAIL"
strSql = strSql & ", M_READ"
strSql = strSql & ", M_OUTBOX"
strSql = strSql & ") VALUES ("
strSql = strSql & " '" & welcomepmsubject & "'"
strSql = strSql & ", '" & welcomepmmessage & "'"
strSql = strSql & ", " & strpmtoid
strSql = strSql & ", " & strpmrid
strSql = strSql & ", '" & DateToStr(strForumTimeAdjust) & "'"
strSql = strSql & ", " & TF
strSql = strSql & ", " & "0"
strSql = strSql & ", '" & 0 & "')"
my_Conn.Execute (strSql),,adCmdText + adExecuteNoRecords
set rs = nothing
'<!-- Send Welcome PM -->
Change the parts in red to your own subject line and message text.<