Need transaction code that will create a customer invoice and process a sendmany

[gojimgo]

I am looking for transaction code that will have multiple output, including an opreturn that I can send to a customer as an invoice who signs the transaction.

In other words, I want to create a transaction using their account for input and they need to use their signature. Once paid, do a sendmany transaction of differing amounts to as many as 5 recipient addresses. I have not yet tried anything because all documentation assumes that I want the bitcoin to come to my bitcoin wallet, which I do not. Can anybody advise me on how to do this? Thanks!

[icanscript]

A website could be set up to do it with different logins.

You could start the skeleton of the transaction which you then send to another user

http://dev.blockcypher.com/?php#creating-transactions

then the user could just put his private key in a one time box that doesn't get stored to sign the tx with his privkey.

[gojimgo]

Thank you! Your suggestion looks like what we need.