set nocount on

if object_id('tempdb.dbo.#company') is not null drop table #company
if object_id('tempdb.dbo.#ProgramAccount') is not null drop table #ProgramAccount
if object_id('tempdb.dbo.#staging') is not null drop table #staging

create table #Company ( CompanyName char(1), Program char(2), ActualReceivedAmount money)
insert #company
select 'A', 'P1', 140000 union all
select 'B', 'P2', 136000 union all
select 'C', 'P2', 76000 union all
select 'D', 'P2', 220000 union all
select 'E', 'P2', 52000

create table #ProgramAccount (Program char(2), AccountNumber int, AccountAmount money)
insert #ProgramAccount
select 'P1', 100011, 24000 union all
select 'P1', 100012, 116000 union all
select 'P2', 100045, 180000 union all
select 'P2', 100046, 304000

create table #staging 
       (seq int identity(1,1)primary key clustered
       , AccountNumber int
       , CompanyName char(1)
       , AccountAmount money
       , ActualReceivedAmount money
       , AccountAmountDistributed money
       , program char(2))

insert #staging
       (AccountNumber
       , CompanyName
       , AccountAmount
       , ActualReceivedAmount
       , AccountAmountDistributed 
       , program)
select p.AccountNumber
       , c.CompanyName
       , p.AccountAmount
       , c.ActualReceivedAmount
       , 0
       , c.program
from   #company c
join   #programAccount p on p.program = c.program
order by AccountNumber
       ,companyName

declare @seq int
       ,@accountAmount money
       ,@acctBal money
       ,@companyRecBal money
       ,@accountNumber int
       ,@prevAcctNumber int
       ,@AcctNumber int
       ,@CompanyName char(1)
       ,@compAcctDist money
       ,@actualReceivedAmount money
select @prevAcctNumber = 0
       ,@companyRecBal = 0
       
select @seq = min(seq) from #staging
while @seq is not null
begin
       select @AccountNumber = AccountNumber
              ,@CompanyName = CompanyName
              ,@accountAmount = accountAmount
              ,@actualReceivedAmount = actualReceivedAmount
       from   #staging
       where  seq = @seq

       if @AccountNumber != @prevAcctNumber
       begin
              select @acctBal = @accountAmount
                     ,@prevAcctNumber = @accountNumber
       end

       select @companyRecBal = sum(AccountAmountDistributed)
       from   #staging
       where  companyName = @companyName

       set @compAcctDist = 
              case
              when @companyRecBal < @actualReceivedAmount then
                     case
                     when @ActualReceivedAmount <= @acctBal then @actualReceivedAmount - @companyRecBal
                     else @acctBal
                     end
              else 0
              end
       
       update s set
              AccountAmountDistributed = @compAcctDist
       from   #staging s
       where  seq = @seq
       and    @compAcctDist > 0

       set @companyRecBal = @companyRecBal + @compAcctDist
       set @acctBal = @acctBal - @compAcctDist

       select @seq = min(seq) from #staging where seq > @seq
end

select companyName
       , program
       , AccountNumber
       , AccountAmountDistributed [ActualReceivedAmount] 
from   #staging 
where accountAmountDistributed > 0 
order by companyName, accountNumber

select accountNumber, sum(AccountAmountDistributed) SumAccountDist from #staging group by accountNumber
select companyName, sum(AccountAmountDistributed) sumCompanyDist from #staging group by companyName

OUTPUT:

companyName program AccountNumber ActualReceivedAmount
----------- ------- ------------- ---------------------
A           P1      100011        24000.00
A           P1      100012        116000.00
B           P2      100045        136000.00
C           P2      100045        44000.00
C           P2      100046        32000.00
D           P2      100046        220000.00
E           P2      100046        52000.00

accountNumber SumAccountDist
------------- ---------------------
100011        24000.00
100012        116000.00
100045        180000.00
100046        304000.00

companyName sumCompanyDist
----------- ---------------------
A           140000.00
B           136000.00
C           76000.00
D           220000.00
E           52000.00

order by program
       ,AccountNumber
       ,companyName