Hallo, i don't understant where is mistake ..
Table = AAA , field pole1 is varchar (100)

declare @tmp varchar(30)
Set @tmp='abcdef'
execute ('INSERT into AAA (pole1) Values( '+ @tmp+' )')

and there is error

Server: Msg 128, Level 15, State 1, Line 1
The name 'abcdef' is not permitted in this context. Only constants, expressions, or variables allowed here. Column names are not permitted.

Help me please, Thanks, Lubo

Execute ('INSERT into AAA (pole1) Values( '''+@tmp+''' )')

jbenson001 is right, becoz u will have to terminate the string inside exec itself.
Atul