Readline

This does most of what you are trying to do... I think.

Global filein = ReadFile("file.txt")
Global Read1$ = ReadLine(filein)
;global Read2$ = ReadLine$(filein)
;global Read3$ = ReadLine$(filein)
;global Read4$ = ReadLine$(filein)
CloseFile( filein )
Print "Read1="+read1
Restore level0
For I=1 To 49
Read read1
Print read1
Next
WaitKey()

.level0
Data "00000000000000000000000000000000000000000000000000";2
Data "00000000000000000000000000000000000000000000000000";3
Data "00000000000000000000000000000000000000000000000000";4
Data "00000000000000000000000000000000000000000000000000";5
Data "00000000000000000000000000000000000000000000000000";6
Data "00000000000000000000000000000000000000000000000000";7
Data "00000000000000000000000000000000000000000000000000";8
Data "00000000000000000000000000000000000000000000000000";9
Data "00000000000000000000000000000000000000000000000000";10
Data "00000000000000000000000000000000000000000000000000";11
Data "00000000000000000000000000000000000000000000000000";12
Data "00000000000000000000000000000000000000000000000000";13
Data "00000000000000000000000000000000000000000000000000";14
Data "00000000000000000000000000000000000000000000000000";15
Data "00000000000000000000000000000000000000000000000000";16
Data "00000000000000000000000000000000000000000000000000";17
Data "00000000000000000000000000000000000000000000000000";18
Data "00000000000000000000000000000000000000000000000000";19
Data "00000000000000000000000000000000000000000000000000";20
Data "00000000000000000000000000000000000000000000000000";21
Data "00000000000000000000000333000000000000000000000000";22
Data "0000000000000000G000003333300000000000000000000000";23
Data "3333333000033333Z333333333333333333333333333333333";24
Data "313F3DZ0000EZ333Z333333363333333333333333333333323";25
Data "3333333000033333Z333333333333333333333333333333333";26
Data "0000000000000000Z000003333300000000000000000000000";27
Data "00000000000000000000000333000000000000000000000000";28
Data "00000000000000000000000000000000000000000000000000";29
Data "00000000000000000000000000000000000000000000000000";30
Data "00000000000000000000000000000000000000000000000000";31
Data "00000000000000000000000000000000000000000000000000";32
Data "00000000000000000000000000000000000000000000000000";33
Data "00000000000000000000000000000000000000000000000000";34
Data "00000000000000000000000000000000000000000000000000";35
Data "00000000000000000000000000000000000000000000000000";36
Data "00000000000000000000000000000000000000000000000000";37
Data "00000000000000000000000000000000000000000000000000";38
Data "00000000000000000000000000000000000000000000000000";39
Data "00000000000000000000000000000000000000000000000000";40
Data "00000000000000000000000000000000000000000000000000";41
Data "00000000000000000000000000000000000000000000000000";42
Data "00000000000000000000000000000000000000000000000000";43
Data "00000000000000000000000000000000000000000000000000";44
Data "00000000000000000000000000000000000000000000000000";45
Data "00000000000000000000000000000000000000000000000000";46
Data "00000000000000000000000000000000000000000000000000";47
Data "00000000000000000000000000000000000000000000000000";48
Data "00000000000000000000000000000000000000000000000000";49
Data "00000000000000000000000000000000000000000000000000";50