While we have to deal with the limitations of the Stock and Option Hacker Scanners not allowing multiple aggregation periods there are several workarounds for your situation... Trading weeks have five days, therefore we can simply look back five days to see whether todays close is within a dollar of the past weeks high...
The following code is most likely the easiest method but only looks back five days from today...
Ruby:
def weekhigh = Highest(close[1], 5);
plot data = Between(close, weekhigh - 1.00, weekhigh + 1.00);
To detect for the previous physical week is more complex and I would defer that answer to one of out Date/Time gurus as I lack the time an patience for the constraint's inherent in Thinkscript... Please let us know if this works for your needs or not...