How to auto +1 increment at text - robotframework

Question

I wanted to append fixed text and +1 behind it.
I have tried to add variable into the text but seems it is invalid.
Test Case
Send Item
[Arguments] ${RECEIVER} ${CLASSIFICATION}
Add item
Choose Mail Recipient ${RECEIVER}
${TIME} Get Time
${TCNUMBER}= ${TC007-00}+1
Add desc [RegressionTestCase][${TCNUMBER}][${CLASSIFICATION}][${SENSITIVITY}] [${TIME}]
error:
No keyword with name '${TC007-00}+1' found.
The expected results are:
TC007-001, TC007-002, etc.

Answer 1

For this case you have to store your number that needs to be incremented somewhere. In my example it is a global variable called ${ID}. You should increment this one using the Evaluate keyword and before that you can simply concatenate it with the base number of the TC.
Based on where you want to do this ${ID} can be a global, suite or test variable, or even local. For more see the User Guide, Using Set Test/Suite/Global Variable keywords.
*** Variables ***
${TCNUMBER_BASE} TC007-00
${ID} 1
*** Test Cases ***
Append Test
${TCNUMBER}= Set Variable ${TCNUMBER_BASE}${ID}
${ID}= Evaluate ${ID} + 1
Log ${TCNUMBER}
${TCNUMBER}= Set Variable ${TCNUMBER_BASE}${ID}
${ID}= Evaluate ${ID} + 1
Log ${TCNUMBER}
${TCNUMBER}= Set Variable ${TCNUMBER_BASE}${ID}
${ID}= Evaluate ${ID} + 1
Log ${TCNUMBER}