Concatenate Variables

I have
Set $VAR1 = {text1}
Set $VAR2 = {text2}

and I need to conecatenate it such that Set $VAR = $VAR1 + $VAR2 + {.png}

how would I do this?

Set $VAR = $VAR1$VAR2{.png}
Or something along those lines. There is no formal concatenation operator