Hi Marbot
Your cavalry may charge through your own Skirmishers but at the beginning of the charge proceedure the skirmishers must retire to rear or the flanks of their parent unit.
They are not allowed to screen the charging unit(Page 23 no 7)
And sorry but you are correct if your infantry columns are pushed back by cavalry they retreat and lose casualties 1 for 1.
I presume the commander who lead your brave columns again'st a Cavalry charge died bravely on the field of battle.(Or did the honourable thing)
It sounds as if you were lucky that the cavalry unit was only 10 strong and not full strength or you wouldn't of had any troops left to retreat.
cheers Kutusov