Hi Mani18.
I think I get the gist of what you're trying to do - should be relatively straightforward but, if I'm right, you're using Bank Feeds / or Bank Import to bring these payments into QB?
Bank Feeds is probably confusing the situation - personally I don't / won't use it (except maybe for reconciling accounts). It can only match transactions in/out of the bank account - it cannot match amounts in/out of Creditors/Debtors accounts, which in effect is what I think you're trying to do.
Anyway ... enter each Standing Order manually - New>Suppliers>Cheque
Cheque Number = Standing Order or BACS or SO (something that you'll recognise, non-numerical otherwise QB will add 1 next time & it will get confused with actual paper cheque numbers).
For Accrual VAT accounting (non-cash basis) I would enter the payment into Accounts Payable (Creditors) with NoVat code.
This would create a credit in the supplier's register which you use to pay the invoice once it's been entered into QB.
You can pay each bill after it's been entered by using the required amount of credit. At the end of the year, the supplier register should be zeroed.
For Cash VAT accounting - you probably know better than me.
Enter into Accounts Payable (Creditors) with 20% VAT code but use NoVAT when entering the invoices?
This creates the same credit to the supplier's register but claims the VAT at payment date rather than invoice date.
Now when/if you use Bank Feeds to reconcile, the system has amounts in the bank register that it can match to.