My government wants to cut 15% of our official development assistance to finance Syrian refugees within our own country (Denmark). What do I do to have them find the money for the refugees from somewhere else than from our development assistance?

"The poorest people in the world are paying the bill."  Really?  Someone is taxing the poorest people to pay for refugees?  Oh, I get it - you consider the handouts that are given to the poorest people to be property they are entitled to.  Handouts that are taken from other people without their individual consent - plunder (Bastiat's term) in other words.  By reducing the plunder they are given, the government is, in effect, plundering them; at least that's how you see it. I suggest you start a campaign of voluntary donations from your fellow citizens, the proceeds of which will go to directly to the poor, replacing what has been taken from your official development assistance (ODA) program.  If the donations are voluntary the donors will be giving freely because they want to, not because they are coerced and threatened with violence if they don't.  Who knows, you may discover that the overhead is lower and, rather than paying the salaries of government functionaries, more of the donated money will go to the poor.

Trying to "find" money in any organization is really, really hard.   Those with excess funds are extremely hesitant to relinquish them for any reason, however good.    Additionally, even identifying excess funds is extremely difficult, no one will step forward and say "I've got extra".   That said, I really don't have a easily workable answer, but it occurs to me that energy prices are falling very quickly.   Perhaps an approach of: "we had x funds allocated to pay for energy, energy is  getting less expensive, let's use the "found money" to pay for ......" Good luck.

One option is for Denmark's policy towards Syrian refugees in Denmark to imitate the Syrian policy towards Palestinian refugees in Syria.  That is, to lock them up in U.N. refugee camps, and train them to infiltrate back into Syria to kill random civilians there until the people from whom they fled are pushed into the sea.

You must be able to propose a logical and cost effective alternate plan that the government will support. Even better if the plan allows them to cut the 15% without sacrificing  the current level of services, care and needs  to the refugees. Denmark and the situation you mentioned may be a good candidate for consideration of "United Shared Savings Network " concept.

the best thing I can think of  is to petition the government and call a press conference, or call a local newspaper for an interview on why they need to have this assistance (assuming, of  course, that they are not terrorists).  You can also speak to some members of Parliament on why this is bad.