hi,
can anyone help me in my problem with rescaling texture

I want to rescale the texture by Adjusting the height without affecting the "other height on top" -> meaning:
Original scale:
A
+++++++ <-- "other height" or A
+ +
+ +
+++++++ <-- i want to reScale my square texture/Image but only the "B" is stretching downwards
B
final output is:
A
+++++++ <-- did not move
+ +
+ +
+ + <-- point C
+ +
+ +
+++++++ <-- this one moved from "point C" as shown above to the current position
B