In that case
=SUM(INDIRECT("'"&B6&"'!H62:V62"))
Note that there are single quotes here, enclosed by double quotes. So, assuming the contents of cell B6 is 00-00-00 then INDIRECT("'"&B6&"'!H62:V62") resolves to the string '00-00-00'!H62:V62 which becomes the argument of the SUM function.
If you make the contents of cell B6 the string '00-00-00' (note: single quotes) rather than just 00-00-00 (note: no quotes) then you can simplify everything to just
=SUM(INDIRECT(B6&"!H62:V62"))

