The procedure presented below for Italian Code DM2008 could be easily adapted for other codes likes EUROCODE 8.
STEP 1. Download and install SIMQKE from http://dicata.ing.unibs.it/gelfi/software/programmi_studenti.html
(if not installed you could install also the common package necessary to run the program)
STEP 2. Select NTC2008 as seismic code or if you have another code directly import spectrum data from the file menu
STEP 3. Set Spectrum parameters (Soil, Service class, Behaviour factor, etc..)
STEP 4. Click on SIMQKE Button
STEP 5. Press Simulated Earthquake button
STEP 6. Export the data and save the txt file. Remove the first two lines from the txt
STEP 7. In Robot add a new spectral analysis
STEP 8. Add a new spectra (Accelaration – period)
STEP 9. Convert Accelerogram saved in txt file to Spectrum
Structural Analysis and Optimization 
Interesting post. However, I have been unable to download Simqke from the links provided. Have they been moved? Regards.
Link updated
hi, would you please tell me how to import the spectrum data? it seems that it should be in a specific format. my program cant recognize text file.
Hi,
once you have exported the txt from SIMQKE, edit the file with the notepad and remove the first two lines. You will get something like
0 -1.87382762145717E-02
0.01 -2.30716146156192E-02
0.02 -1.52940891799517E-02
0.03 -1.77843840653077E-02
0.04 -4.43096634582616E-03
Save the file.
In Robot, in the “Response Spectrum Calculation” Dialog, select the tab F(t), then press the button “Open from a file”, switch to “all files types” and select the previous file