Conversion Error With SQL Command String

Hi,

When I use the folowing code, the first (green) line is executed well.
The composed SQL statement (red) gives a conversion error.


declare @vchSQL_Cmd varchar(max),

@intMaxNr int,

@vchTabelNaam varchar(255),

@vchKolomNaam varchar(255)



set @vchTabelNaam = 'CI_Lei_Toestand_DetailLijnen'

set @vchKolomNaam = 'CameraInspectieID'



select @intMaxNr = max(CI_Lei_Toestand_DetailLijnen.CameraInspectieID) from CI_Lei_Toestand_DetailLijnen

select @intMaxNr


set @vchSQL_Cmd =

'select @intMaxNr = max(' + @vchTabelNaam + '.' + @vchKolomNaam + ') from ' + @vchTabelNaam

select @vchSQL_Cmd

exec (@vchSQL_Cmd)

select @intMaxNr


Thx