If you don't already have an
CTakeDamageInfo instance on hand, you'll probably need to use something like
Source Scramble to allocate one, set up the desired values, then pass its address. Refer to
game/shared/takedamageinfo.h in the Source SDK for how it's laid out.
However, it does seem like you're posting about an attempt to solve a different problem (
the XY problem) -- what are you actually trying to solve, if anything?