G-code's application case problem

[wuxinyuanyuanyuan-coder]

I have a specific application case: starting CNC movement from position X0 Y0, needing to move to X0 Y100, with the requirement to perform laser cutting specifically within the segment from X0 Y10 to X0 Y90. The cutting in this middle segment needs to be at a constant speed. My initial idea for the code is roughly as follows, but it doesn't work properly in actual execution (feed rate F600):

G1 X0.000 Y0.000
G1 X0 Y100 when X=0 Y=10.000 M3 S500 when X=0 Y=90.000 M5 S0
G1 X5.000 Y100.000
G1 X0 Y0

I would like to ask everyone how to adapt and write the G-code for lasergrbl to meet this requirement. I am looking forward to your help.

[wuxinyuanyuanyuan-coder]

I think it might be possible to achieve this functionality by performing pre-calculations related to the P command, but I still can't manage to write G-code that can be properly read.