It sounds weird in French too
Indeed, that would be "until", but it doesn't make much sense. I'd think of:
"if needed, when V. comes online, I'll give him my money." or
"if needed, as soon as V. comes online, I'll give him my money."
I'd say that to use "till" or "until" the line could be something like:
"if needed, till V. comes online, I'll have given him my money." (I'll give him the money and afterwards he comes online)
See what I mean?