Agreed - there should be no apostrophe there, but there should be quotes here:
Let vMAXTIMEms = Num(peek('time_mill',-1,'data_table'));
This assumes that the qvd load is sorted by time_mill. i would also ensure that it is a number with Num(). Otherwise you should do this:
LOAD max(time_mill) As maxTime
From .... (qvd); // or resident....
Let vMAXTIMEms = Num(peek('maxTime'));
DROP Table temp;