MID$
The MID$() funcition returns <length> characters from a sring, starting from <position>.
Syntax
MID$(<input$>, <position>, <length>)
Warning
Unlike in CBM BASIC, the character position is zero-based, i. e. the first character's position is 0.
Example
DIM in$ AS STRING * 30 in$ = "xc=basic programming language" PRINT MID$(in$, 9, 11) : REM outputs: programming