The challenge almost ran out of steam when the High Court threw the challenge out and the UKUUG realised it didn't have enough money to file an appeal.
But Alain Williams, UKUUG chairman, said: "We are trying to raise a bit more but we've got sufficient backing to appeal and go forward."
He refused to say who had refilled his war chest and with how much money.
Microsoft's ISO certification got suspended after official complaints from Brazil, India, South Africa and Venezuela, while the EU has started investigating whether there were any improprieties in the process that gave Microsoft its gong.
The BSI has stood by its decision to back Microsoft's standard. But the UKUUG's challenge, which consists of a request for a judicial enquiry, asserts that the BSI may have breached its rules.