Expansion of variables inside single quotes in a command in Bash

I want to run a command from a bash script which has single quotes and some other commands inside the single quotes and a variable.

e.g. repo forall -c '....$variable'

In this format, $ is escaped and the variable is not expanded.

I tried the following variations but they were rejected:

repo forall -c '...."$variable" '

repo forall -c " '....$variable' "

" repo forall -c '....$variable' "

repo forall -c "'" ....$variable "'"

If I substitute the value in place of the variable the command is executed just fine.

Please tell me where am I going wrong.