replace bitmap by another entities bitmap

I got a pointer to the entities bitmap (via vmap_for_entity)m say A - and I got a Bitmap B (from another entity) - so it's not a file.

Now I want is to assign Bitmap B to A.
The ent_morphskin method allows me to do this - but expects a filename.
But I just got a pointer to bmap data.

What command may solve this?

got it solved
bmap_blit