Matlab upload files and process data

Hello guys, first of all thanks to everyone and excuse my English, I hope you can help me! I have a problem and I wonder if you can, before uploading on matlab in a .txt file that contains a row carattereri (huge), like this example:

[{"point":{"x":1073,"y":35,"all":[{"x":1073,"y":35}]},"time":"12:53:48"},{"point":{"x":1093,"y":61,"all"[{"x":1093,"y":61}]},"time":"12:53:48"},...

(This continues for each instant of time (time))

I would like to know if it is possible to extrapolate or save for a specific time range (eg from 24:53 to 12:58) the x and y coordinates that are precisely before "time" in the uploaded file; in order to make the analysis of these coordinates found (for example if they are at a particular point that interests me) loading these in a dynamic array in two columns or other structure which is useful for me ..

I ask for help because I can not fix Thanks again!!!