The GUS basic script language is a subset of what people normally think of as as VB. There was actually a Honeywell IAC specific VB interpreter written for the GUS product.
Although you could test out a VB algorithm in a standard tool like visual studio, you could not take the code intact and move it to the GUS environment: You would have to edit it some.
I have actually done what you are suggesting, and I found the translation from regular VB to LCN 'VB script' to be tedious: the algorithm was complex, however, and I do think it saved me time over all.
A Caveat: I have not worked on GUS for over 3 years. Some of what I described to you may be superceeded by new releases. FYI: I wrote the LCN_loat.pct, lcn_client_load.lct and ucn_load.pct pictures that are used for system diagnostics.
Chris Schene
(former TDC/LCN/GUS Software Engineer)