Trimming field line curves using length

[karuna.kannan]

i want to trim these curves according to a particular length, (50 units)
I’ve attached grasshopper file as well
can somebody please help?

MAG field lines on site.3dm (324.2 KB)
MAIN MAG FIELD.gh (34.5 KB)

[HS_Kim]

Something like this?

MAIN MAG FIELD_re.gh (24.0 KB)

[karuna.kannan]

yes its working now
thank you very much