I'm new to Inkscape and although I find it pretty easy to use I cannot seem to find a solution for my problem, or rather for my unresolved matter as it sounds more positive and motivated

Anyway, I am designing a logo with three letters, it is a semi serif font but I want to copy the top left serif of the capital M to the lower right. Now, how exactly can I achieve this? I've tried copying the entire glyph, turned it upside down, clipped it to the right size and it looked right but when I export the project, I have white spaces in my transparent background. Also, the vector points wont show up on the new serif part of the letter, no matter what I try... I am not sure I am able to draw the serif in there to it looks similar either as I am not a graphics designer (like at all...) or let's say YET because it is, again, a nicer way to say it.
Can someone point me in the right direction?