Can I use my hand to my wives vagina during her menstruation for pleasing her? With or without any pajama?

All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.

If your wife is menstruating, then it is not permissible for you to use your hand in her vagina because this will entail directly touching impurity (the menses blood), unless this is done by placing an obstacle to prevent your hand to directly touch the impurity.

If you are safe from touching impurity, then there is no harm in doing so.

Allah knows best.