Batch file: Find if substring is in string (not in a file)

Question

In a batch file, I have a string abcdefg. I want to check if bcd is in the string.

Unfortunately it seems all of the solutions I\'m find

Answer 1

To find a text in the Var, Example:

var_text="demo string test"
Echo.%var_text% | findstr /C:"test">nul && (
    echo "found test" 
    ) || Echo.%var_text% | findstr /C:"String">nul && (
             echo "found String with S uppercase letter" 
    ) || (
             echo "Not Found " 
    )

LEGEND:

1. & Execute_that AND execute_this
2. || Ex: Execute_that IF_FAIL execute this
3. && Ex: Execute_that IF_SUCCESSFUL execute this
4. >nul no echo result of command
5. findstr
6. /C: Use string as a literal search string