Replace a character in sql file

Hi 

I have a sql file which contains some create tables steps for exampl.

Create table databse.abc

As select * from original database.abc where status ='active' option lable='$inc'

Now i have to replace this '$inc' with some other text in power shell file 

I tried to declare that $inc there in the script of powershell but some how its not replacing table is getting created but $inc is not getting append

For ex.

String= "'$inc'=12345'"