In this particular situation I would do the following,
note, assuming you have xml tools plugin installed and that
delay tag as well as type tag keep their values.

1. copy the block into e new buffer

<MouseMovement>
	<Type>3</Type>
	<x>0</x>
	<y>0</y>
	<Delay>7</Delay>
</MouseMovement>

2. goto plugins->xml tools->linearize xml

<MouseMovement><Type>3</Type><x>0</x><y>0</y><Delay>7</Delay></MouseMovement>

3. press ctrl+d as many times as you want it to be replicated

<MouseMovement><Type>3</Type><x>0</x><y>0</y><Delay>7</Delay></MouseMovement>
<MouseMovement><Type>3</Type><x>0</x><y>0</y><Delay>7</Delay></MouseMovement>
<MouseMovement><Type>3</Type><x>0</x><y>0</y><Delay>7</Delay></MouseMovement>
<MouseMovement><Type>3</Type><x>0</x><y>0</y><Delay>7</Delay></MouseMovement>
<MouseMovement><Type>3</Type><x>0</x><y>0</y><Delay>7</Delay></MouseMovement>
<MouseMovement><Type>3</Type><x>0</x><y>0</y><Delay>7</Delay></MouseMovement>
<MouseMovement><Type>3</Type><x>0</x><y>0</y><Delay>7</Delay></MouseMovement>
<MouseMovement><Type>3</Type><x>0</x><y>0</y><Delay>7</Delay></MouseMovement>
<MouseMovement><Type>3</Type><x>0</x><y>0</y><Delay>7</Delay></MouseMovement>
<MouseMovement><Type>3</Type><x>0</x><y>0</y><Delay>7</Delay></MouseMovement>
<MouseMovement><Type>3</Type><x>0</x><y>0</y><Delay>7</Delay></MouseMovement>
<MouseMovement><Type>3</Type><x>0</x><y>0</y><Delay>7</Delay></MouseMovement>
<MouseMovement><Type>3</Type><x>0</x><y>0</y><Delay>7</Delay></MouseMovement>
<MouseMovement><Type>3</Type><x>0</x><y>0</y><Delay>7</Delay></MouseMovement>

4. put the caret after <x> and press and hold SHIFT+ALT and use down arrow key to create a rectangular selection
5. press the del key to get rid of the initial value
6. start column editor (menu edit->column editor) and set your start end end number. (you can’t set negative values) press enter.
7. repeat the step for y value
8. Create another rectangular selection and add the minus sign
9. goto plugins->xml tools->pretty print … with line breaks

Sounds alot of steps but is done within seconds.

Is the a way to efficiently add more lines easing in from 0 to -24

I think you are hoping that a regular expression (regex) would read the 24 and the 0, then find a “middle” number and produce another set of intermediate instructions. A regex cannot perform mathematical calculations, so for any high number and any low number it cannot calculate a middle number.

However all is not lost, as Notepad++ also supports other programming languages and also plugins. PythonScript is a well supported language (and well used by Notepad++ users), but it would require learning it to do your task or relying on someone within this forum to produce a program for you.

Terry