Amend formula to pull pivot table information to be generic

[jb00976]

I have the following formula that pulls information from a pivot table:

=GETPIVOTDATA("[Measures].[Sum of Client OS]",Portfolio!$A$3,"[Table4].[Acc Mngr]","[Table4].[Acc Mngr].&[Joe Smith]")

I am putting this formula into a sheet called Summary where cell A5 is the name Joe Smith. I would like to be able to change the above formula to use the cell A5 instead of having the actual name there so that I can paste the formula into cells below and it will pull for other names. If I just replace Joe Smith with A5 I get !REF. I have tried removing brackets and quotation marks and I can't get it to work.

Thanks in advance for any help.