How to calculate size of a folder located on different machine(Remote) in sql server 2008?

Question

DECLARE @TenantId UNIQUEIDENTIFIER ='A79ED820-2E5E-4A9D-B930-B7597DC97081'
DECLARE @BusinessName VARCHAR(200)
declare @line  varchar(255) =''
declare @path varchar(255)=''
declare @command varchar(255)=''
DECLARE @folderSizeGB decimal (16,8) = 0
DECLARE @AttachmentDiscSpaceUsed decimal (16,8) = 0
-- Code to calculate folder size in GB BEGINs
            IF OBJECT_ID('tempdb..#temp') IS NOT NULL
            drop table #temp
            create table #temp (line varchar(255))
            --set @path = '\\ewp-dev18\\c$\\Attachments\\' +  CONVERT(varchar(50),@tenantId)
            set @path = '-S ewp-dev18 -E -i ewp-dev18\\c$\\Attachments\\' +  CONVERT(varchar(50),@tenantId)
            set @command = 'dir "' + @path +'"'                               
            insert into #temp
            exec master.dbo.xp_cmdshell @command
            select
            @line=
            ltrim(replace(substring(line, charindex(')', line)+1,
            len(line)), ',', ''))
            from #temp where line like '%File(s)%bytes'
            SET @line=
            (Case WHEN @line IS NULL or @line ='' THEN '0' ELSE @line END)
            set @folderSizeGB  = Cast(Replace(@line,'bytes', '') as decimal)/1073741824
            if (@folderSizeGB is null )
            set @folderSizeGB =0
            SET @AttachmentDiscSpaceUsed = @folderSizeGB
            SET @path=''
            SET @command=''
            SET @line=0
            -- Drop #temp table
            IF OBJECT_ID('tempdb..#temp') IS NOT NULL
            drop table #temp
            -- Code to calculate folder size in GB ENDs
            

Answer 1

hello RSingh,
Once again thanks for your cooperation,
I applied the script you posted, but it is not giving me the size of the folder which is located at a remote machine. Please note the " I need to calculate the size of the folder which is located at a remote machine".and when i applied its path in your script,
it raises "Access is denied" error message.
My path is - '\\ewp-dev18\c$\Attachments'
EXEC getFileProperties '\\ewp-dev18\c$\Attachments'
and this folder does not have any sub folders, it contains only some txt files, image files or some doc files. so no issue of sub folder.
and about my remote server 'ewp-dev18', i have all access and rights, but still raising "Access is denied". why?
do i need to pass any login credential with it ???