Transfer of text items between text waves

I have data from several analytical measurements combined with a corresponding sample code in a text wave. After performing calculations to track analytical errors I wish to create a new text wave containing only the sample codes of the wrong samples.

In a first attempt I simply wrote, as is usual for numbers:

samplecode1[k]=samplecode2[m]

This does not work. Then I tried to write a sample code to a string and to read it into a new text wave:

string_test=samplecode1[1]
samplecode2[0]=string_test

This works perfectly in the Command window but not in a program. Sofar, I did not find any hint how to achieve this simple operation.

Thanks for your input!

Hans